They fit perfectly, I would suggest taking a size up, my daughter wears a 10/12 which is medium, they are a bit small, she has a small waist. and the big ones suited her better, the material is really good so no complaints.
Pros
My kids love it, they are comfortable and definitely durable as they love to jump and run.
Cons
Size Difference: Although this product is designed for little girls, there may be size differences that may cause discomfort or difficulty in fitting correctly.