Without knowing any of the details, the Ruth Lawrence thing struck me as absurd, really damaging, her father very much 'needed his head checking'.
Whatever professional or academic field the hothousing parent wants his or her child to ultimately succeed in [something like pro sport is different, a poorly adjusted brat can certainly succeed there], the child will as an adult need to repeatedly interact with other people, with a halfway normal childhood being the tried-and-tested way of building the skills we need to do that as adults.
e.g. there was a kid in my class at school who was probably about as good at maths as a Ruth Lawrence, but the parents there did absolutely the right thing, yes the child quietly sloped off in year 8 or something to sit A level maths, and thereafter didn't show up to regular maths classes, doing some kind of private study instead, but every other lesson, including sports and so on, took place with appropriately aged peers, and university started at the normal age. in RL'c case, going to university aged 12, with no opportunity to make friends, have boyfriends, etc, was utter madness.