Like ALovelyLady86 said, in the state of Georgia, 17 is legal. I don't know how other states are, but that's how it is where I live.

I personally don't see anything wrong with it. She's mature enough to have a relationship. If you really care about someone, I don't think age should matter, especially if it's only 4 years. As long as she's not under the age of 17, then you're not breaking the law, and there's nothing wrong with it.

I know a guy who's 25 or 26 and he's dating a 17 year old. No one says anything about it.