Reading Chapter 7 again I came across this:
In summer 1980, Camden social services brought a "day fostering" scheme into effect for Nicholas and Daniel. Far from fostering in the usual sense, it simply involved child-minding on a daily basis with extra support for Sheila. Twenty-three-year-old Judith Jackson, married with two children of her own, cared for the twins every weekday for a few hours. Her home near Parliament Hill fields was a fifteen minute walk for Sheila and the twins; when Judith later moved to Highgate, social services arranged transport.
Of course those wishing to go on painting Colin in a bad light, or rubbishing Carol Ann Lee's book can go on making up their own stories.