My DH is the same with my DD, she dresses pretty sensibly for a 15 year old when she goes out, meaning she doesn't wear crop tops with her hipsters etc. but if she has a tshirt on that is a bit shorter and a bit of belly shows, he will want her to change it. It's a bit hard not to show a bit of belly with the only jeans you can buy being hipsters and most t's are pretty short..... Most of her friends wear crops and little singlet tops, but she isn't comfortable wearing them.
She has a mind of her own and wont let other kids talk her into doing things she doesn't want to do which is a huge relief iykwim...
Btw Tanya, nothing wrong with the length of that dress