"I purchased the small tween size for my 6yo. She normally wears a 6x or 7. This size was perfect for her. The costume is thin, but what do you expect in a halloween costume? Haven't tried the leggings on so I don't know if they will be too big or not. The hat is flimsy. Would be nice if the bill was supported more so it didn't fall in her face. I will fix that with some cardboard or something."