Im 56 and 105 lbs, 34A. I got XS, which is my normal size. The material is sooooooo soft!!! I can pull it down and wear leggings with it (it covers about 3/4 of my butt). Or I can scrunch it up and wear skinny jeans or skirts or shorts. I have small hips and XS fits nicely. If anyone has hourglass figure or a bit larger hip, Id suggest getting at least a bigger size than normal size. The top part is flowy, so it might be ok for a B or C? Im not sure about D.