I went to boarding school from 11-16. It was normal at my prep school for the girls to go at 11, and boys left at 7. I'm 30 now.
I really liked the idea of boarding school and was happy to go, but when got there, realised quite quickly it wasn't for me. My father used to work abroad constantly, so I already had a lot of separation anxiety from him and being away from the entire family unit affected me badly. I would cry constantly to go home.
The first month of school we were not allowed to use phones to contact our parents - which was particularly hard. We had to 'sign in' three or four times a day too so our housemistresses knew that we were 'safe.' If they noticed we weren't eating as much, you would be weighed and monitored at meal times by checking in - or having to sit with a teacher to eat.
On one hand, being amongst a whole group of girls my own age meant that you always had friends around to cheer you up - so I tried to just get on with it in the first few years. Housemistresses and our matrons were also amazing.
By age 13 however, I knew i wanted to leave, but GCSEs were fast approaching, so I was not allowed to leave until I had completed them. The large influx of new girls into our year group at 13 definitely affected our safety bubble at boarding school and led to a lot of teenage politics and drama between friend groups.
Everytime I was able to go home I would start crying when it was time to go back and I constantly felt ripped apart from my family.
The girls that really enjoyed the experience seemed to be the ones who had grown up rurally, and perhaps did not have many friends around them or closeby enough to foster proper, consistent friendships. So they loved it.
Pretty much all of the girls from London in my year group ended up leaving for 6th form - as it became apparent especially in later years that being stuck out in the middle of the countryside was effectively 'missing out' on family life, and more exciting life at home, in the city. I'm glad I didn't stay there until 18, as I think i'd have had a much harder time adapting to coming back to London...
Not for everyone - but if you don't live in an area where your children have close proximity to other kids, playdates and freedom to go out and play with their friends it's definitely worth considering.