In the US: Southeastern New England

[Little BabyDoll Christine]

This kind of place was calle "Nursery School". and was really for 4 year olds and is now called the generic Pre-K (I attended one such in 1950)

You would also be surprised how prominent diapers were for little girls. They were used on 2 hour trip or longer and in many causes for girls under 8 or who could not hold it comfortably for more than 2 hours when 2 or more of them were part of a group of girls staying at someone's house for a good long time, like an afternoon; immediately after lunch to about 4: 30 or quarter to 5. Both of these were quite common as this was before the 60 mph interstate system begin in c1956 or so and in the calse of a group of girls staying at someone's house, usually one of their number, the parents; usually Mommy, did not want the bathroom being used every 45 minutes or so and the increase in water usuage and the attendant increase in the water bill (having lived through the Great Depression, of which memories were still fairly fresh and this being the age of the five gallon toilet). Also girls played with dolls much more and learning to dress and change them was part of growing up. In fact, a little girl who got one or more pair of full size baby panties and "real"diapers for her "dolly box" was very proud. And the funny thing is, most girls had  them

The reason it pertained to girls more than boys was boys tended not to stay in one place for long and could find a place to relieve themselves in a wooded area or vacant lot and on the long inter-city trips, there were enough wooded areas where one could pull the car over next to and a man or boy could jump out, go behind a tree and "see a man about a horse"