We ordered one size up so we could throw it in the wash. It's a cute, comfortable dress for summer and camp !
This dress runs on the smaller side to begin with (I bought a size 8 at first, for my 7 yo who's wearing size 8 tottini dresses, and returned bc it was too small and bought a size 10). But then, even though I washed it cold and hang-dried, it shrunk a TON and was too short by Shavuos (not quite brushing the bottom of her knee). We ended up buying the 12 when it went on sale.
Buy big, or expect to waste time and money.
Cute dress, though. And my daughter enjoys wearing it.