Kim was originally meant to be flat to contrast with how curvy Bonnie was. The creators said that censors didn’t allow that though, and they didn’t want to simply make her smaller because it would be too subtle of a difference and it’s just in the nature of animation to go off model here or there so there would inevitably be parts of the animation where the animators interpret her as being the same size as the other ladies. Their solution was to make her pointy, to convey she’s less endowed than everyone else. So “canonically,“ she’s supposed to be small. Kind of.