Around 4-5, IIRC, and at size 5 US clothes diverge in terms of waist circumference. SK is indeed giant, and the stair-step effect is really cute. (Reason is apparently still half an inch taller than the Pip, which surprises me because I was sure that her relative-to-agemates tallness had dropped off by now. No one in Reason's near ancestry has topped 6' except for my maternal grandfather, oddly enough; I doubt that such a remove has influence.)