Well, how much younger is she? I have been in that situation many times, as the younger female under the consent. I think in most states you can still date her, but you cannot have sex with her. So, maybe you can be patient and wait for her physically.

My parents never really made an issue about me dating an older man as long as they approved and he was not too old, the rule was nobody older than my brother. So, no gap larger than five years until I was 18.

So, maybe you should see what her parents think. Sure, it is not the law but it is better to have their approval first. I think that there is a lot of hope for you if you can win their approval and you keep your relationship private from the public.