As long as she doesn't try and convert you, who gives a shit. However, the longer you date, the more likely that you'll just eat what she eats and become quasi vegetarian (I say this because you'll still have a steak/burger with your friends etc)
Oh, and just you wait until she's comfortable enough to start dropping bombs in front of you. According to a friend, his wife's vegetarian farts are room clearing powerful
Good luck OP!