Paranoid friend. What to do?

So my girlfriend, lets call her Katie, is not exactly average. The only thing about her that is average, would be her height. She's got big eyes and a double eyelid, full lips and a straight nose. I swear she looks mix. Here's the catch. She's the most unconfident girl I've met. She hates her legs. Thinks her tummy is fat and doesn't like her body. But she is just paranoid.

Anyone have some advice for her?