I ordered a size medium for my 8 year old, but she is also very thin and tall. It fits great, some of the edges are rough and cause a slight irritation on the skin so an undershirt may be required, but overall the costume is very cute. It is not too short and the arm and leg covers help because we live in snow country and trying to keep my daughter warm while she is trick or treating can be difficult but this costume makes it easy to add for temperature changes. It is durable, and will turn into dress up clothes after Halloween.

UPDATE:

This costume does not come with the wig, but I chose not to get it. I ended up purchasing a snow princess crown instead because every experience I have ever had with a full wig was disastrous and it just added on a cost to a halloween costume that seemed unnecessary.