The skirt I would say size down in. I got a small and I would have went with a XS. Jacket is true to size. Sweater- size up for a better oversized fit. Boys are all in true to size. Boys wear the same size. They have very different statures but both average a 7 and boys small tops. Tom’s in a larger flannel LTKStyleTip LTKFindsUnder50 LTKFindsUnder100