Aha! just the inspiration I need.
Tan let us know how you find that pattern. Now they have upsized it for bigger girls (cos my 4yo needs a size7 for arm and body length) I want to make one for her with a fleece on one side.

oops me. I'm going to pull apart two bathrobes the ILs gave DH and I a couple of years ago and make some coverups for the kids at swimming lessons.