I love Malory Towers as much as any nostalgic overgrown child person, but I think one thing that makes the stories so compelling is precisely that the parents aren't around, which forces the girls to make their own child-centred community, only really communing with the adults (the teachers) when absolutely necessary.
This makes for really exciting fictional stories, but the reality would be very different indeed imho. Adults aren't just there to teach or discipline you, but also to ground you and make you feel secure. They (usually) love you unconditionally, whatever you do, because you are their child; whereas the teachers, however kind and lovely they may be, are only there in place of your parents for potentially weeks on end because they are paid to be there.
How would you feel if your spouse told you that they loved you very much indeed, but that they would rather just see you every month or so and live most of their life apart from you, in a community of other (as yet unknown) people?
I'm not talking about those serving in the armed forces, working on oil rigs or trawlers or otherwise having to be away for their job; but if they could freely live with you day in, day out, but they just actively decided that their life would be better, more enjoyable, more fulfilling if they lived elsewhere without you there for weeks or months?
I can't imagine most people being prepared to put up with that with a very significant adult in their lives; but these are children as young as 11, or even younger.
I also don't get the reasoning that, because the child really wants it, that must make it the best decision. Most children would really love to eat nothing but Easter eggs and Haribo for their entire diet, year-round, but that doesn't mean that we, as the responsible adults, actually let them make that decision.