I always tell my boy, his voice is beautiful and I love hearing him to sing. One day he suddenly sang and asked " mommy, is my voice beautiful?"
I think he really believes what I told him. So, you have to tell your kid she is the most kind and lovely child. Tell her that you only love kids whom are kind, polite and humble....regardless of appearance. And explain to her our appearance will change and beauty will fade as we grow older. It is more important to have inner beauty.
And you can always buy some pretty dresses to make her more adorable!