I have seen a few young kids in school uniforms on the tube in London. Most, but not all, seem to have a chaperone. Two or three young kids traveling together is not unusual. We only noticed it because it is becoming unusual to see kids walking to school even here in rural America. They all get dropped off until they are old enough to drive (14/15 here). It probably does not help that community schools are getting replaced with massive schools on the outskirts (where large parcels of land are still available) of town.
