I see I'm the "odd woman out" here. Because the cats have to be kept separated, each has 1 bowl for dry food, one for wet food, a cat milk bowl, and at least one water bowl on any given day (ZsaZsa, our indoor-outdoor, part-time cat, has access to the laundry room only, so she only has one water bowl; Jamie has free run of the house, and has three water bowls and a fountain). That's a lot of bowls, seeing as the dishwasher is only run every other day!
As long as there aren't any spats, and both kittens are getting enough to eat, I don't see any problem. I do find that spreading water bowls throughout the home encourages the kitties to drink more.