Hi Moo,
It sounds like you're threatened by your girlfriend looking good. Does she make you feel that you are not enough for her? Or is it that she spends too much time on her appearance?
I can see how you wouldn't value beauty without good character and personality first. Perhaps you would like her to concentrate on those values more than
just looking good.
There is nothing wrong with looking good but it shouldn't be the most important thing.
If she tries to look good just to feel better about herself and it isn't working, then she doesn't
love herself herself very much.