There are some things I don't like about this. First, flirting with someone through an RPG seems like a bad idea. Just ask them out if you want to date them, and don't creep people out (her or others) by using the roleplaying as an excuse to live out your fantasies.

Second, most people play roleplaying games to experience being someone they aren't. If she is a tiny woman IRL wouldn't it make sense for her to be a hulking brute? You should try playing someone that isn't like yourself sometime, it's very fun and can teach you a lot both about yourself and others.