I orders a medium for my 11 year old who is 4 feet 11 inches tall and 132 lb and wears a women's size 6. I am very impressed with this modest bathing suit. The material is great quality. The inserts for the top cover up her up nicely. However, I do not think this is a good bathing suit for someone who requires a lot of support for their breasts. The high waist is perfect for her short torso. I would surely order again and I'm satisfied with the price.