The waist is about 19” and it wouldn’t be hard to adjust this. Since the legs are just made by halving the end amount of stitches, you can just adjust the amount of stitches, making sure you have an even number.

There is a matching hat for this (look for Blue Shell Hat) and both items were created to match this the crochet dress in Baby Layettes, its by Leisure Arts and has a knit pattern as well. The shorts and hat would look cute with other things as well, though.

The dress is for a newborn but my Mom made it fit a one year old by just increasing the hook size. Then I made these shorts and the hat to match.