Oh wow. =) You raise some questions that are wonderful questions and ones that parents, clergy, homosexuals, AND physicians have been asking themselves for many years. =)
I'm willing to bet that no one will have a true, definitive answer to what makes someone a homosexual for a very long time. Until then.... it is important to let your daughter, or any loved one that is homosexual, that while you may indeed be concerned for their future, that you accept them as how they are and that your ultimate wish is for them to do what will make them feel the happiest and most comfortable with themselves.
I understand your concern; life is a bit more difficult for a homosexual. But life can be difficult for any NUMBER of reasons, you know? Life is now more difficult for me because I have used poor body mechanics over the past little while and thus, I now officially have degenerative disk disease, and have already had to have surgery for a herniated disk.
And, keep one thing in mind... she may indeed just be experimenting, even though she has dated more than one girl.
I understand also, that you live in an area that may be less than accepting of homosexuals. But, you know, if she is indeed gay, she may decide to attend college in a larger city that is perhaps more accepting.
(Let me say though, that when I was going to that little college where you live =), I knew quite a few gays. There was a bit of a community there. )
Lots of luck and love, to you and your stepdaughter. :redbeathe:redpinkhe