I get what you're saying op but here's the thing.....
You're only 20 so it's not like there's things you can do that she can't. 2 yrs isn't bad at all. No one would joke on you for that either. You can't get into 21 and up clubs and she can't either. And if you're in the U.S neither one of y'all can drink. So it's no biggie.