Hey, a few friendly notes on this as someone who's PIP is about the prevalence of gay fanfiction (so in a similar zone to you!):
-I recommend checking out the 1997 book 'textual poachers' by Henry Jenkins (you can get it on an interlibrary loan pretty easily) and emailing Dr. Georgia Carroll from Sydney University about questions/arranging an interview over Zoom with her. She's a great help, knows a lot about fandom as she did a PhD in popular culture around the commodification of Taylor Swift and how fandoms react to that.
-It's important to recognise that fangirls aren't the
only way of being a fan, there's a whole mixture. If you're talking about music specifically then you should definitely mention boybands, the general stigma around being a female fan of pop music vs the accepted intenseness of male-dominated rock music, etc etc. Even if it's not your cross-cultural it's important to acknowledge!
-Look up the pdf 'Ethics in Fan Research' by Ruth Deller if you're engaging with fans on a researcher-to-subject basis. Researching something you're a fan of puts you in a precarious ethical position when researching and gathering primary info (eg do the fans know you're gathering info on them? Have you asked permission to use tweets/images/memes from the creator?), and this pdf has helped me steer clear of the worst of the unethical rocks so far.
-Finally - and this is just personal - I think you should be a bit clearer in the questionnaire, 'Who are you a fangirl of?' is a little vague.. 'Which musical artist are you a fangirl of?' would be more direct. No pressure tho, it's fine as it is. Questionnaire is very succinct apart from that