Im not defending her, personaly i dislike most of her art because it is just the same thing over and over, and not beeing too interesting.
But have you maybe considered that proportions, and beeing anatomicaly correct isn't really the purpose of art like that? Its suposed to be enjoyable and pretty and well rendered thick animu girls. And her beeing successful is pretty good proof that it accomplishes just that.
Its just not suposed to be the study of anatomy.
If you see a pretty landscape of a scenery painting do you point out how colors aren't realistic, or how moon is too big? Whats the point of it other than beeing petty.