Disney Princess Anna Girls Costume Dress Frozen Halloween Dress Up Size ?

Dress is in good, pre-owned condition. Small blemishes on the underskirt lining-I haven't tried to wash them out. Fastens in back with 2 hook/loop closures. There is tulle in the skirt for volume. NO SIZE TAG. Approx measurements lying flat: 10" waist, 12" pit to pit. 36.5" long (top of sleeve to bottom of dress).