I recently purchased size small (4-6) for my almost 6 year old (she'll be 6 next month). She is 43" and somewhat small, but not terribly. I worried cause next to the "size 4-6" it states for ages 3-4, I took a chance anyways. It fits her fine - we both like it very much - it's really cute! She normally wears a size 5. Don't be mislead by the "ages 3-4".Get more detail about Supergirl.
