I exchanged the med top for a large. I'm 42" in the bust & 13" at the top of the arm (where sleeve hits). I ware and 8 - 10, never 12. So, if you're my size go for the large. This is a beautiful outfit. The drape is lovely (skirt cut on bias). The skirt have ample room for my 8-10 size, hit's your curves (because of the cut), beautiful drape and gentle flouncy hem line ... beautiful. The top will still pull (slightly) because there is no stretch/give. Even though the (shirt)size is large in the body it has a lovely drape. If you're on the fence ... go for this one, it's truly as beautiful as the photo. I love it.
I have the shirt and skirt in medium. The top is too tight across the bust and arm, there is no lycra in the material, so no give. I'm 42" around the bust and 13" at the arm where sleeve hits. I'm usually a medium but need to return this for a large (hope it fits). The color is lovely, the material is light and has a nice drape. This is a pretty outfit. There is no special or detailed tailoring in these garments.