Don't worry, she clearly proved by that statement she is one of those "pretty dumb" girls. But, you have to give her props for trying to make you feel better. She probably didn't know what else to say. If you are constantly badgering her about it, she probably knows she can't just say, "Nooo... that's not true..." anymore. Learn there are more important things in life, you will grow, and she will be stuck having to survive on her good looks, while you get ahead in life.