I make regular crib sheets, and I don’t see why a quilted one wouldn’t work. I would definitely use a very low loft 100% cotton batting or even just a layer of flannel. My crib sheets are made from a 2 yard piece, cut 8” boxes out of the corners, sew the boxes, and add elastic. I use an elastic application foot on my serger, but a casing will work (though a lot harder in a quilted sheet.