Well, Martorama, you just failed the Gina Ford/Jem Russell School of Parenting - remember that bit in one of the Tyrol books where David, who is a small baby, is crying in his pram in the garden, and Jem forbids a desperate Madge to pick him up because it will spoil him? And Madge obeys. (Jem being an expert on childcare, despite this being his first child too, because he is a Great Doctor, and they know everything, including how to instil a sense of discipline in infants.)
Mind you, he seems to manage it with the Robin, though I suspect she's actually a cyborg.
Or he uses mind-altering drugs. The Chalet School doctors are always dosing their wives without telling them, having taken over from Matron, who seemed to spend her entire life dispensing either sleeping drugs in hot milk or castor oil to deal with 'greed'.
There's one obvious reason why Malory Towers and St Clare's are better than the Chalet School, and that's the fact that MT and SC have a constant stream of successful midnight feasts, where people eat pork pies and tinned peaches at 3 am, have a great time, and don't get caught, whereas at the CS, any poor attempt to eat something after lights out is either immediately detected by Matron, or involves all involved throwing up violently the next morning and being dosed.