Clothes do not make the person. If she's having low self esteem, do something to boost it...like a makeover at your local Sephora's they do them for free...or do your alls hair. If she wants "cool" clothes, let her earn them.

Like my mom made me do at that age is...write out what I love about myself like my fav thing is my lips that could be one thing she can list. What she don't like...and write ways to change that. She also made me write or say one good thing about myself a day.

Have her pick a role model like ummm mine is either Eva Longoria or Nicole from the pussycat dolls....they are both beautiful people.

hope that helps!!