soontobe, why would anyone shout at you for that- this is of course what we all, I hope at least, believe. Absent's post says it all.
And of course every child is beautiful, in their own way. However, in order to know how to proceed, it would be helpful to know if she is distorting the reality in her mind, or if she is a bit /or more overweight or has features which are not, today, considered as 'beautiful'. Stopping the distortion in the mind is very different to helping her accept who she is and see all the good things and perhaps help here make changes that will help her.