My then-teenaged son "came out" to his dad and me several years ago (as "bi"). His dad is far from homophobic, but I'd say he was, um, concerned--I guess the way many parents are concerned that their kids will grow up and be OK.
Anyway, that was the last we ever heard of it. He's had quite a few girlfriends, but no boyfriends that I've ever heard about. Possibly there was some experimentation that happened somewhere along the way, or thoughts about it. Or maybe he keeps that part of his life private--though he's pretty open about his life.
I guess my point is that given the way her dad is, unless and until it becomes an issue he needs to know about, probably discretion is the better part of valor. He might wind up making her feel terrible about herself. And by the time she is a little older she may feel differently (or maybe not--but hopefully she will be mature enough by then to feel secure in herself regardless of dad's reaction).