This is a beautiful costume and worth every penny.  My little girl was delighted when she opened her Christmas gift.  I would suggest you go a size bigger.  My daughter is 6 years old and I got her a large. It  fit her perfectly (if you want it to glide across the floor like a real princess gown).  It also has a hoop under  the gown to keep it poofy.  She wears it every chance she gets, and it has held up wonderfully.