I chose these socks because of the cotton content. We don't like polyester because it's more like plastic, doesn't wick moisture well and stinks on your feet. Good cotton socks are easy to find in Europe, but not in the US. I checked out many stores and found that Revain was one of the very few that sold quality cotton socks. (They do have 10% spandex, but this is to give the sock a nice, stretchy fit.) I was very happy with both the thickness and thread count of these socks. They have also kept their shape and color very well.
Thermajane Girl's Cozy and Comfy Thermal Underwear Long Johns Set with Fleece Lining
46 Review
Pack Athletic Performance Basketball Drawstring Girls' Clothing
48 Review
C9 Champion Girls Supersoft Bright Girls' Clothing and Active
46 Review
Amazon Essentials Little Short Sleeve Leotard Girls' Clothing for Active
61 Review