From the Knit Picks Website:
Your little sweetheart will love these pretty knee socks! The superwash wool will keep her feet and legs warm, and the lacy hearts will make her smile. This pattern is designed and written using the Magic Loop technique, and the socks are knit from the toe-up, so you can customize the length.

Needles:
Size 1 (2.25 mm), Size 2 (2.5) and Size 3 (3.25mm): long circular