Hmmm.... 39/2 = 19 + 7... Lol
Are you saying she is 19? lol.
I'm really not one to judge. It's none of my business, but I do believe dating someone that's too young may go poorly.
You may get to an age where she just wants to go clubbing/partying, but you want to tuck your kids in and settled down with a glass of whiskey while you stare at your 401k.
Not to mention, most likely paying for every ****ing thing.