Size M swimsuit, size chart on site I purchased it from: https://spreepicky.com/products/nier-automata-2b-cosplay-swimsuit-sp1711440

I think this would fit someone 5'3" or under with pretty small hips/bust measurements.

It has a pretty cute neckline with the mesh fabric, and soft built in bra cups. Snaps at the neck and a side zipper. Actually pretty well made for store-bought cosplay. Free shipping in the U.S.! I'm also selling this in size L (neither fit me, so sad).