Remembering back to when I had a baby girl...I would have preferred the pants and all be one piece because of the way they will gap and the dress part will ride up. Just be sure they accommodate diaper changes without stripping the child for a chilling IMO. However you decide to do it, that will be a really sweet outfit.
Cheating is an option. . . . Cheaters never win and winners never cheat, but smart knitters who want to retain an iota of sanity do, cheerfully. ~~Kory Stamper