In Your Notes please specify what size as follows:

CHILD-BOY/UNI (unisex/boxy) + XS (4/5), S (5/6), M (7/8), L (9/10), XL (11/12) 

CHILD-GIRL (slim cut/cap sleeve) + XS (4/5), S (5/6), M (7/8), L (9/10), XL (11/12) 

ADULT-MALE/UNI (unisex/boxy) + S, M, L, XL, XXL

ADULT-Female/V-neck (Slim cut) + XS (0/2), S (4/6), M (6/8), L (8/10), XL (10/12), XXL (12/14), XXXL (14/16)