By all accounts,,Sheila wanted the boys " toughening up " a bit,as they weren't boisterous as boys are known for.Instead,they were quiet,gentle little souls,,thin and on the nervey side.
They used to visit the park in Maida Vale,where they lived with Sheila after Colin had left,,which may have affected them too,as boys need a father. No little friends to play with though. No trees to climb.