A friend was looking for a Halloween costume for her dd. She found an outfit on an American website.
www.aokdress.com/black-and-white-polka-dot-printed-girls-kids-child-children-toddlers-growth-gymnastics-practice-latin-dance-dresses-sets-ruffles-off-shoulder-top-and-skirts.html
At the very bottom it says and I quote...
"if the girl is a little fat, please use a larger size"
Not sure if my link has worked!