I've already reviews this in another spot, but for others to see - I got a medium and it fits well. It comes up short in the back so you have to be careful. The material gets wrinkled easily, but otherwise it's good and is super comfortable on. I'm 130 lb and 5'8" for reference.
If I could go back and change I would've order two sizes up I normally wear a small, and I would recommend buying a large if you normally wear a small. Because the arms are little tight and was a little short for my liking. But it's still so super cute