This is a lovely skort, excellent quality, and such fun! I showed this to the Mother of the 8 year old this was purchased for and she remarked, "She will wear that to the treads!" That said i initially purchased the small and immediately realized I needed to exchange for the medium. The young lady this was purchased for is turning 8, is slender, and athletic. I have purchased her a medium in Nike running shorts and they are a bit large, but have a drawstring adjustment. I prefer they grow into an item that will always at some point be useful.