I've seen it more related to traumatic abuse, usually sexual, but also physical or mental. In either case, I wonder if either situation pertains to Maya Keyes?
There's another aspect to people become homosexual. Recruitment - seduction by an older homosexual. Very frequent among homosexuals. Not saying it happened in the case you mentioned. Also, consider rebellion. Many teenagers rebel against their upbringing, sometimes seriously, sometimes mild. But if the rebellion includes sexual experimentation with the "gay" life - and then acceptance of the lie that "if you've had one gay experience, you're gay forever and ever" - that could chart a path in life such as hers.
I hope that she takes advantage of reparative therapy and her she and her family are reconciled.