I think it means "person trying to fit in while still exhibiting a bit of personal style"--where the crowd she's trying to fit in with is one that considers "femme", "agender", Wicca/paganism/whatever, and the practice of proudly declaring one's sexual identity to be normal things.  "Witchy person" is probably not standard jargon the way "femme agender" is, so there's her little personal touch. Probably the meanings these people assign to those various concepts are not as important as that basic fact:  that this is a dumb kid trying to be friendly with, and cool around, other dumb kids.  (And also, that there are many young people today who know far more about superficial sorts of social tolerance for various minority groups than they do about human physiology or nutrition.)