It might be worth mentioning that boys and girls at my primary school didn’t play together. There was a separate fenced-off area of the playground for the reception class; apart from that, there was a concrete playground for the junior boys, and a larger playground including a grass playing field for the second and third year infants and the junior girls. There were separate entrances for the boys and girls, too.
At Halstow, there were still entrances marked, but not used, separately for boys and girls-I believe they were contemporary with the school’s founding-1893. Infants had one common entrance which WAS reserved for them, ditto one complete side of the building’s playground.