It's possible she's afraid/nervous to come out of the closet or "not ready to admit it" and let it slip that she was bi on accident or "unconsciously", but normally maintains the mask of being straight or something?
To complex for here, there's a lot of other potential variables at play like are her close family/parents very conservative/religious? Is your area hard right leaning?
Ana also finds female genitalia gross
I generally only hear that from people who're going through an internal struggle between who they feel they are and right-wing upbringing/programming
Well that's weird then.
Do you want to pursue something more with your friend? If not, I'd just drop it.
If you do, id tread carefully based on what you know of them and cautiously open deeper dialog on what they ment