I get Mode magazine which has beautiful pictures of full size women and I show them to my daughter. I do say things like "My that woman is beautiful" But most of all I tell her that all humans are beautiful and that artistically bodys are beautiful to draw. (I have drawings from an old art class.) I'm fortunate, she does have a good body image in her head. Now my problem is the fact she is worried about makeup and if she "has" to wear it. Oh my daughter is 14.
As for DeeSinn, My son was the same way at 4 about his body image. Unfortunately he was raised with the low fat diet Mother and now that I'm Atkins he's confused. He doesn't like meat (if you don't count hamburger and hot dogs)
He's 11 now and has a much better image of himself. He's trying to eat more meat but his such a carb junkie.
So just keep up what you are doing and they will be fine. Honest!