is my daughter in a harry potter cult?

Last week my wife and i were out for the night, but returned early. We
saw our 16 yr old daughter on the computer, on a strange picture
website, and she was crying. She told us she has made many friends on
this site, and they all have "common interests" and that "this was the
end of their lives." When i told her i no longer wanted her to be on
this site, she panicked and accused me of wanting her to be "forever
alone" and that I "just didn't understand"

The reason I'm so concerned is that this was a webpage she had made,
made entirely of images of the harry potter cast, and two strange
young gay men in school uniforms, and many references to "voting" and
something called "the warblers" and lines saying this was "the end of
an era", she has also recently become more tired, and had less sleep,
due to using the internet.

Is she in some strange harry potter worship cult led by these men? Are
the electing a new leader? Any insight to this would be wonderful, as
we have never seen this kind of behavior from our daughter before.