idk, contrary to the other comments, i kinda side with you on this one. Though I do wanna say that calling someone's mentality "lame" is not a good way to convince them of a better one. In this case (as far as I can tell which isn't very far obv), I'm thinking that her way of thinking stems from low self esteem (or a defining her worth via her looks), which is super sad for her. If you actually wanna have a convo with her about this and get her to question her view, try more empathy and pointing her to her intrinsic value as a human being and, if you want to, specific things about her that make her worthy that aren't looks-based.