Little girls

I have always taught my two girls (ages 17 and 11) to be who they want to be, to not let anyone push them into who being someone they're not. My oldest daughter has done this beautifully. She's had her moments of doubt and fear, but struggled through and is a wonderful person. I'm very proud of her turning into the kind and compassionate adult that i have watched her grow into.My youngest daughter however, is just the opposite and I worry about her. She isnt as strong willed as her sister and tends to 'follow the crowd'. The problem is, that she has always been a 'bigger' girl...compared to the string beans she's in school with and who she sees on t.v. and I think that's adding to her self doubt.It makes me so upset because she is so kind and sweet and beautiful in EVERY way!!!!!! i try to keep telling her t hese things, but what i say isnt what's 'important'... anyone who has a girl this age know's what i'm talking about just wondering if anyone has any advice on this because i dont want her to think she's less than anyone.. ever!!