I love the advice here and I would add to it: Having sexual fantasies that include gender switching also doesn't necessarily make you gay or trans- Kinsey showed that femail sexual arousal can be fluid enough to encompass a variety of fantasies that don't actually affect day to day gender identity. So I'd say that she may be trans, or bi, or gay AND/OR she may be a hetero cisgender female for whom being male in a sexual fantasy signifies a different power dynamic she's trying to explore... After all, the mechanics of male arousal are much more commonly pictured in pop culture- sometimes an inexperienced female might find it simply easier to imagine orgasm through masculine eyes. I am glad, however, that whatever she discovers about her sexuality and its intersection with her gender identity that she feels she has a resource like this to get questions answered with empathy and respect.