Harper is 10 and wears size 10-11y. If you prefer a more standard/ cropped fit you can size down.
Garment measurements by size (approx):

Size (cm) 1Y 2-3Y 4-5Y 6-7Y 8-9Y 10-11Y 12-13Y
Chest 36 41 44 47 50 53 56
Length 39 45 49 53 57 61 65