Did she sign up on friendica.world as well, or another server?

She should search (in the search field up top) for katelynne@friendica.world to find you,
or you can search for her (nick)@(server).

It may be that she'll have to wait a bit to "get connected", if she just signed up.
(I assume she's already got the registration e-mail with her temporary password.)

Personally, I've been quite a bit in the diaspora* sphere - actually more than in the Facebook sphere - but my plan is to pull the plug on Fb somewhat later this year, and I haven't got anyone from Fb to join me at diasp., but Friendica has Calendar events which (for me) is the only missing part that diasp. doesn't, so we'll see if I get people with me this time.

(Probably not, but ... oh, well.)

This space is, as with most "new (for me)" things, a bit confusing and disorienting - I think mainly "how does the different feeds work?" for now.
We'll see. Time will tell. For now, it's time to sleep. *proceeds to go comment on more posts 🙈*

Okay, here is my first try at the DARK MODE variant! Set your Friendica theme to "Frio" and the Theme Customization to either "Dark" or "Black" and Save your settings. Then copy and paste the code below into your user stylesheet and restart your browser. If you're using Firefox wrap all of it inside of @-moz-document domain(friendica.world){...} (or whatever domain you're on). Hopefully this works, I don't know what the character limit is here.

/* FRIENDICA MODS V2 DARK MODE */
body {
       background-color: #1C1C1D !important;
       font-size: 15px !important;
       padding-top: 125px !important;
}
#topbar-first .nav > li > a, 
#topbar-first .nav > li > button, 
nav.navbar .nav > li > a, nav.navbar .nav > li > button{
       color: #B0B3B8 !important;
       
       }
#topbar-first, nav.navbar {
       background-color: #252728 !important;
       color: #B0B3B8 !important;
}
       #topbar-first .topbar-nav .nav-segment {
              margin-right: 10px;
       }
       #topbar-first .nav > li > a:hover:not(.selected) {
              background-color: rgba(255,255,255,.1) !important;
              border-radius: 8px !important;
       }
       .fa-lg {
              font-size: 24px !important;
       }
#topbar-first .nav > li > a:hover, 
#topbar-first .nav > li > a:focus, 
#topbar-first .nav > li > button:not(#main-menu):hover, 
#topbar-first .nav > li > button:not(#main-menu):focus, 
nav.navbar .nav > li > a:hover, 
nav.navbar .nav > li > a:focus, 
nav.navbar .nav > li > button:hover, 
nav.navbar .nav > li > button:focus {
  background-color: rgba(255,255,255,.1) !important;
       border-radius: 8px !important;
       
}    
#topbar-first .nav > li > a.selected {
       border-bottom: 3px solid #0866FF !important;
       color: #0866FF !important;
}
#topbar-first .nav > li > a.selected:hover,
#topbar-first .nav > li > #main-menu:hover,
#topbar-first .nav > li > #main-menu:focus {
       background-color: transparent !important;
       border-radius: 0 !important;
}
ul.tabs li {
       font-size: 15px !important;
       margin-left: 10px !important;
}
ul.tabs li.active {
       border-color: #0866FF !important;
}
       ul.tabs li a {
              margin-top: 8px;
              color: rgb(90, 167, 255) !important;
       }
       ul.tabs li:hover:not(.active) {
              border-bottom-width: 0px !important;
       }
              ul.tabs li:hover:not(.active) a {
                     background-color: rgba(255,255,255,.1) !important;
                     border-radius: 8px !important;
              }
        .dropdown-menu {
            padding-bottom: 15px !important;
        }
            .dropdown-menu li {
                margin: 10px;
                width: 92% !important;
                border-radius: 8px;
            }
                .dropdown-menu li:hover {
                    border-color: transparent !important;
                }             
header #banner {
       left: 0 !important;
       right: auto !important;
}
       header #banner #logo-img,
       .navbar-brand #logo-img {
              background-color: #0866FF !important;
       height: 40px !important;
       width: 40px !important;
       }
.topbar ul.nav {
       left: 50% !important;
       margin-left: -25% !important;
       position: relative;
}
#topbar-first .nav > .account img {
       border-radius: 100% !important;
       box-shadow: 0 0 1px rgba(255,255,255,.1) !important;
       height: 40px !important;
       width: 40px !important;
}
#search-box {
       position: fixed !important;
       left: 100px;
}
#topbar-first #search-box .form-search {
       height: 40px !important;
       font-size: 15px;
       background-position: unset;
       box-shadow: none !important;
}
#search-box form > div {
       background-color: #333334;
       border-radius: 50px;
}
#search-box form > div::before {
       content: '\f002';
       font-family: ForkAwesome;
       position: absolute;
       left: 10px;
       top: 8px;
}
#search-box .form-control.form-search {
       border-radius: 50px !important;
       background: transparent !important;
       width: 100% !important;
}
#search-box .form-control::placeholder {
       color: #B0B3B8 !important;
}
#topbar-first #search-box .btn {
       font-size: 0px !important;
         height: 32px;
       width: 32px;
       top: 2px !important;
       background-color: black !important;
}
#topbar-first #search-box .btn::before {
       content: '\f061';
       font-family: ForkAwesome;
       font-size: 15px;
       color: #B0B3B8;
}
#nav-user-menu, #nav-notifications-menu {
       background-color: #252728 !important;
       border: 1px solid #1C1C1D !important;
}
#nav-user-menu {
min-width: 250px !important;
}
.nav-pills .dropdown-menu li a, 
.nav-pills .dropdown-menu li .btn-link, 
.nav-tabs .dropdown-menu li a, 
.nav-tabs .dropdown-menu li .btn-link, 
.account .dropdown-menu li a, 
.account .dropdown-menu li .btn-link, 
.contact-photo-wrapper .dropdown-menu li a, 
.contact-photo-wrapper .dropdown-menu li .btn-link {
       color: #B0B3B8 !important;
       border-color: #252728 !important;
}
       .nav-pills .dropdown-menu li > a:hover, 
       .nav-tabs .dropdown-menu li > a:hover, 
       .account .dropdown-menu li > a:hover, 
       .contact-photo-wrapper .dropdown-menu li > a:hover, 
       .nav-pills .dropdown-menu li.selected a, 
       .nav-tabs .dropdown-menu li.selected a, 
       .account .dropdown-menu li.selected a, 
       .contact-photo-wrapper .dropdown-menu li.selected a {
              color: #333 !important;
              background: #f2f2f2 !important;
              border-radius: 8px;
       }  
.nav-pills .dropdown-menu li.divider, 
.nav-tabs .dropdown-menu li.divider, 
.account .dropdown-menu li.divider, 
.contact-photo-wrapper .dropdown-menu li.divider {
       background-color: #252728 !important;
}    
#topbar-first #nav-notifications-menu {
       border: 1px solid #1C1C1D !important;
}
#topbar-first #nav-notifications-menu li {
       border-color: transparent !important;
box-sizing: border-box;
       margin: 10px;
       border-radius: 10px !important;
       width: 94% !important;
}
#topbar-first .notification-unseen {
       background-color: rgba(56, 88, 152,.2) !important
}
#topbar-first #nav-notifications-menu li.notif-entry:hover{
  background-color:rgba(128,128,128,.2) !important;    
         border-color: transparent !important;
}
#topbar-second {
       height: 60px !important;
       background-color: #252728 !important;
       border-color: #333 !important;
}
       .btn.btn-primary:hover,
       .btn.btn-primary:focus {
              border-radius: 8px !important;
       }
       #dropdownMenuTools {
              height: 40px;
              width: 40px;
              background-color: rgba(255,255,255,.1) !important;
              border-radius: 100% !important;
              margin-top: 5px !important;
              margin-right: 10px !important;
       }
              #dropdownMenuTools:hover,
              #dropdownMenuTools:focus {
              background-color: rgba(0,0,0,.1) !important;
       }
       #jotOpen {
              border-radius: 8px !important;
              background-color: #0866FF !important;
              color: #ffffff !important;
              border-color: #000 !important;
              box-shadow: none !important;
       }
       #jotOpen:hover, #jotOpen:focus {
              box-shadow: inset 0 0 100px rgba(0,0,0,.1) !important;
       }
       #jotOpen::before {
              content: 'Compose';
              font-size: 15px;
              margin-right: 10px;
              line-height: 32px;
              position: relative;
              display: inline;
              top: -4px;
       }
       #jotOpen .fa-pencil-square-o {
              font-size: 32px !important;
              position: relative;
              top: 4px;
       }
       #topbar-second #nav-short-info {
              margin-top: 10px;
       }
/* Other people profiles */
#mention-link {
border-radius: 8px !important;
              background-color: #0866FF !important;
              color: #ffffff !important;
              border-color: #000 !important;
              box-shadow: none !important;
       padding: 0 16px !important;
}
       #mention-link:hover,
       #mention-link:focus {
              box-shadow: inset 0 0 100px rgba(0,0,0,.1) !important;
              
       }
       #mention-link span:first-of-type {
              float: right;
              font-size: 32px;
              top: 4px;
       }
       #mention-link span:first-of-type .fa-2x {
              font-size: inherit !important;
       }
       #mention-link span:last-of-type {
              font-size: 15px;
              margin-right: 10px;
              line-height: 32px;
              top: 6px;
              position:relative;
       }
#contact-edit-status-wrapper {
       margin: 15px 0px !important;
       border-radius: 10px;
}
/* sidebar widgets */
aside .widget,
.nav-container .widget {
       background-color: #1C1C1D !important;
       -webkit-box-shadow: none !important;
       -moz-box-shadow: none !important;
       box-shadow: none !important;
}
.tread-wrapper {
       background-color: rgb(37, 39, 40) !important;
  box-shadow: 0 0px 1px rgba(0,0,0,.5) !important;
  border-radius: 10px !important;
}
.wall-item-container .media {
       background-color: rgb(37, 39, 40) !important;
       border-radius: 10px !important;
}
.well {
       -webkit-box-shadow: none !important;
       box-shadow: none !important;
}
       .contact-photo,
       .contact-photo-xs {
              border-radius: 100% !important;
              border: 1px solid #252728 !important;
       }
.hovercard {
       background-color: #252728 !important;
       border: 1px solid #1C1C1D !important;        
}
       .hover-card-pic img.thumbnail {
              border-radius: 100% !important;
              background-color: #1C1C1D !important;
              border-color: black !important;
       }
       p.wall-item-announce,
       .media .time, .media .shared-time,
       .media .delivery, .media .location,
       .media .location a {
              font-size: 13px !important;
       }
              .type-link, .type-video {
                     padding: 0 !important;
                     margin:  0 !important;
                     background-color: rgb(51, 51, 52) !important;
                     border: 1px solid rgb(101, 104, 108) !important;
              }
              .type-link h4, .type-link blockquote, .type-link sup,
              .type-video h4, .type-video blockquote, .type-video sup {
                     padding-left: 10px !important;
                     padding-right: 10px !important;
              }
       /* ACTION BUTTON LABELS */
       .wall-item-actions-row button,
       .wall-item-actions-right button {
              display: block;
              white-space: normal !important;
              margin: 0 auto !important;
              -webkit-box-shadow: none !important;
              box-shadow: none !important;
       }
       .wall-item-actions-row button::after,
       .wall-item-actions-right button::after {
              font-size: 14px;
              font-family: sans-serif;
              display: block;
              margin-top: 2px;
       }
       .wall-item-response {
              overflow: visible !important;
       }
       .button-comments::after {
              content: 'Comment';
       }
       .button-announces::after {
              content: 'Share';
       }
              .share-links .dropdown-toggle::after {
                     content: 'Share';
              }
       .button-votes::after {
              content: 'Quote';
       }
       .button-likes::after {
              content: 'Like';
       }
       [id^="dislike-"]::after{
      content: 'Dislike';
       }
       .wall-item-actions-right .dropdown-toggle::after,
       .more-links .dropdown-toggle::after {
              content: 'More';
       }
       .wall-item-response span {
              position: relative;
              text-align: center;
              display: block;
              background-color: #0866FF;
              box-shadow: -1px 1px 1px #000;
              border-radius: 4px;
              color: #fff;
              font-size: 12px;
              font-weight: 700;
              width: fit-content;
              padding: 0px 7px;
              margin-left: 55%;
              top: -62px;
              z-index: 1;
       } 
      .vote-event:not(:has(.wall-item-response:empty)){
            padding-bottom: 135px;
      }
      .vote-event .wall-item-response{
            position: absolute;
            top: 63px;
      }
      .vote-event .wall-item-response:empty{
            display: none;
      }
      .vote-event .wall-item-response:nth-of-type(1){
            left: 15px;
      }
      .vote-event .wall-item-response:nth-of-type(1) .button-event::after{
            content: 'Going';
      }
     .vote-event .wall-item-response:nth-of-type(2){
            left: 105px;
     }
     .vote-event .wall-item-response:nth-of-type(2) .button-event::after{
            content: 'Can\'t Go';
     }
     .vote-event .wall-item-response:nth-of-type(3){
            left: 204px;
     }
     .vote-event .wall-item-response:nth-of-type(3) .button-event::after{
            content: 'Maybe';
     }
       /* END OF ACTION BUTTON LABELS */        
#profile-photo-wrapper {
    overflow: visible !important;
    padding: 5px;
    background-color: #1C1C1D;
    border-radius: 100%
}
aside .widget li {
    margin-bottom: 8px;
}
aside .vcard img.u-photo, aside img.vcard-photo {
    border-radius: 100% !important;
    box-shadow: 0 0 1px rgba(0,0,0,.3);
    border: 3px solid #1C1C1D;
}    
aside .widget h3.p-name {
    font-size: 32px !important;
    text-align: center;
    word-break: break-word;
}
aside .vcard .p-addr {
    font-weight: 600;
    text-align: center;
    white-space: break-spaces !important;
}
aside .widget li.selected {
    background-color:rgba(56, 88, 152,.2) !important;
    border-color: transparent !important;
    border-radius: 8px;
}
aside .widget li.selected a {
    font-weight: bold;
}
aside .widget li:hover {
    background-color:rgba(128,128,128,.2) !important;
    border-color: transparent !important;
    border-radius: 8px;
}
#widget-contacts {
    background-color: rgb(37, 39, 40) !important;
    border-radius: 8px !important;
    box-shadow: 0px 1px 2px 0px rgba(0, 0, 0, 0.2) !important;
}
       .contact-block-img {
            height: 100px !important;
            width: 100px !important;
            border-radius: 8px !important;
            box-shadow: 0 0 1px rgba(0, 0, 0, .2);
            margin: 5px;
       }
.comment-fake-form {
    border: none !important;
    background-color: transparent !important;
}
.comment-fake-form textarea {
    border-radius: 50px !important;
    background-color: rgb(51, 51, 52) !important;
    box-shadow: none !important;
    -webkit-box-shadow: none !important;
}    
.wall-item-actions button {
    font-size: 24px !important;
    color: #B0B3B8 !important;
}
       .wall-item-actions button:hover {
              color: #0866FF !important;
       }
       .wall-item-actions .checkbox {
              padding-top: 6px !important;
       }
       .comment .media-body {
              padding: 10px;
              background-color: rgb(51, 51, 52);
              border-radius: 20px;
       }
       .wall-item-actions-row .wall-item-emoji {
              font-size: 18px;
              line-height: 40px;
       }
       .navicon {
              font-size: 20px;
              position: relative;
              top: 1px;
       }
/* not obviously clickable or intuitive what it does */
        .plink.u-url::before {
            Content: 'Link: ';
        }    
.img-allocated-max-width {
       margin: 20px auto;
}

/* Photo Albums */
.photo-album-actions .icon-padding,
.photo-edit-link-wrap .icon-padding {
    margin-left: 10px !important;
}
.photos-upload-link {
    font-size: 28px;
    color: #0866FF !important;
    opacity: 1 !important;
    border-radius: 8px;
    padding: 0px 8px;
}
#photo-album-link {
    opacity: 1 !important;
}
.photos-upload-link i,
#photo-album-link i,
#photo-edit-link i,
#photo-toprofile-link i,
#album-edit-link i,
#album-drop-link i,
.photos-order-link i {
    font-size: 24px !important;
    color: #0866FF !important;
    opacity: 1 !important;
    border-radius: 100% !important;
    padding: 8px 11px !important;
    height: 40px;
    width:  40px;
}
#photo-edit-link i.fa-image {
    padding: 6px 7px !important;
}
.photos-order-link {
    margin-top: 5px !important;
}
    .photos-upload-link:hover i,
    .photos-upload-link:focus i,
    #photo-album-link:hover i,
    #photo-album-link:focus i,
    #photo-edit-link:hover i,
    #photo-toprofile-link:hover i,
    #photo-toprofile-link:focus i,
    #album-edit-link:hover i,
    #album-edit-link:focus i,
    #album-drop-link:hover i,
    #album-drop-link:focus i,
    .photos-order-link:hover i,
    .photos-upload-link:hover i,
    .photos-upload-link:focus i {
       background-color: rgba(255,255,255,.1) !important;
    }
.photos-content-wrapper .photos-upload-link::before {
    content: 'Add Photos';
    font-size: 15px; 
    vertical-align: middle; 
    margin-top: -10px;
    display: inline-block;
}
.justified-gallery {
    overflow: visible !important;
}
.justified-gallery > a, 
.justified-gallery > div, 
.justified-gallery > figure{
    height: 180px !important;
    width: 180px !important;
    border: 1px solid #ccc;
    position: relative !important;
    top: auto !important;
    left: auto !important;
    border-radius: 8px;
    margin: 4px !important;
}
.justified-gallery > .jg-entry-visible > img,
.justified-gallery > .jg-entry-visible > a > img,
.justified-gallery > .jg-entry-visible > svg,
.justified-gallery > .jg-entry-visible > a > svg{
    width: 100% !important;
    height:  100% !important;
    margin: 0 !important;
    top: 0 !important;
    left: 0 !important;
    object-fit:cover;
    object-position: center;
}
#photo-photo {
    margin: 0 auto !important;
}

@media screen and (max-width: 1280px) {
    #search-box { 
        width: 18% !important;
    }
}
@media screen and (max-width: 991px){
    #search-box {
        left: 15%;
    }
    #jotOpen::before {
        content: '';
        margin: 0;
    }
    #mention-link span:last-of-type {
        margin-right: 42px;
    }
}
@media screen and (max-width: 768px){
    #topbar-first .navbar-toggle[data-target="#search-mobile"]{
        position: fixed !important;
        left: 15%;
    }
    #search-mobile {
        top: 110px !important;
    }
}

So I finally saw some posts with "Events" so I could see how that worked. It didn't look so good:

So I restyled this with arguably the most convoluted bit of CSS that I've ever written so it conditionally adds space for a second horizontal row of buttons and then puts the buttons in that row like this:

I edited the action button and dark mode stuff above with the change. The line that makes the magic happen is this one:

.vote-event:not(:has(.wall-item-response:empty)){...}

Now that is some freaking alchemy!

But the .vote-event container itself is NEVER empty. It ALWAYS has three boxes in it. So I needed a way to check if the container has empty boxes in it, and if it doesn't then add space for a second row of response buttons. Such fun when you have no control over the document's structure. 😜