hmmm...my ds is a scooter too and we don't have this problem, we use cloth nappies, the brand is bum-genius, not sure if that's why we dont get this problem...also he can take the tabs off himself so I always put a cover over the nappies, either bloomers, or shorts or pants or some kind...maybe that would help keep it in place? Or maybe try going down a size? It wont be long before she stops scooting in circles though, I can promise you that!
xo