I got these for my 4 year old and they fit perfectly. They don't seem to stretch that much and may not fit her in the long run but are great for probably a year or 2.
12-Pack of Jefferies Seamless Sport Socks for Boys
45 Review
Jefferies Socks Boys Seamless Toe Crew Athletic Socks 6-pack
47 Review
Aminson Grip Ankle Socks: Non-Skid Slipper Crew Socks for Kids Boys and Girls - 6/12 Pairs
49 Review
π Premium Prince Athletic Socks - Active Black Boys' Clothing for Top-performance
45 Review
Arctix Youth Pants Reinforced: Large Boys' Clothing for Active Adventures
46 Review
Boys' Adidas Active Sports Tricot Athletic Clothing
45 Review
π Bold Pack Sleeve Active Hoodie Sweatshirt Set for Boys' Clothing - Stylish and Comfortable!
47 Review
Waterproof Cozy-Dry Rain/Snow Pants for π§ Kids by JAN & JUL, with Fleece Lining
64 Review