I ordered this costume for my 4 1/2 year old (who is a bit tall).
I ordered the small b/c it said size 4-6 on the website.  However when it arrived, and she put it on, it was extremely small.  I looked at the package it came in and it said 3-4yr.

She will need the next size up...so Im returning it.  Other than that... standard quality halloween costume and oh so cute!  She loved it... Ill have to return and re-order in secret!