Bobo are you talking about England or France? From your posts over the years, it is very clear that the French have a completely different approach to parenting and education, and attitudes in both countries cannot be compared.
It happens:
- ask any inner city sixth form teacher and they will give you examples. I had a colleague who had lived alone from the age of 16 and whilst continuing her education, though close to her family. It was apparently normal in her community.
- there will be some attending something specialist, like drama school or perhaps as you suggest, a very academic day school.
That said, Westminster had clear rules that sixth formers should not be left home alone during term time. John Rae, a former Head, includes a sad story in his memoirs about a boy committing suicide whilst both parents were away, so I assume there was some experience. Similarly SPGS says:
4.11 Residence during term time The Pupil is required
during term time and at weekends to live with a
Parent, unless otherwise agreed in writing by the
High Mistress.
4.13 Absence of parents When both Parents will be
absent from the Pupil’s home overnight or for a 24
hour period or longer, the School must be told in
writing the name, address and telephone number for
24 hour contact with the adult who will have the care
of the Pupil
I have come across Paulinas who, back in the day, were sent from Scotland to live with some elderly aunt in order to attend the school. This does not happen now, but it will not be unusual for two working parents to struggle to juggle diaries.