Couple problems with a few things in here. First of all, science hasn't proven homosexuality to be natural. Science doesn't prove anything; It accumulates enough evidence to label things as truth, but science is constantly being debunked. Anyway, being any sort of minority is "natural" and that doesn't make treatment towards minorities any kinder.
Honestly, adopting infants isn't that easy, they're highly in demand. It's the older children that have a hard time finding a home. And by that point, they're old enough to consent to living in a gay household, so if the child is alright with that, I think that's fine. An infant doesn't have a choice, so I don't agree with that.
Speaking as a female, growing up would have been difficult without my mom. I don't want to talk to my dad about all my girly issues. But this is a problem in single households as well.
Honestly, it's a difficult subject, and things like this are more often than not circumstantial. It'll definitely work out for some children and not for others, just like children in straight households have good and bad childhoods. It's not a black and white subject.