Girls long sleeve gray shirt

There are no tags of any kind on this shirt. No brand, no size, no care instruction, not even where it's made. The arms are crochet on. comparing this with other girls' shirts, I estimate it's a size 10/ 12 girls. This blouse is adorable and in great condition. arm pit to arm pit :16 in top to bottom: 20 in long sleeve: 21 in.