Um. It's good to remind yourself about distorted body image not just for your girls but for yourself. You don't deserve it any more than they would. (Though it's probably easier, especially when you're tired, to remember not to do it for their sake.) And I think beating yourself up for your mothering / role model skills may fall into the same category: unfair to you (who work so hard and do so well at it) as well as a bad example.

But as far as the role modeling goes, I'll echo others' comments and note that it can be helpful to see that even strong people have weak moments.