aw hon. *hugs* While she might say she's not a lesbian, I don't think one *has* to be a lesbian, or straight, or bi, to love whomever one loves. Some things transcend what's in or not in someone's undies... You're still the same person, after all. You've just grown a bit.
Ack. Would she love you any less if you dyed your hair blue, for instance? It's not your personality, or heart, that's changing, it's just your body.
*rant rant rant rant rant*

hang in there...