Answer by Alison Hill, Familiar with the English boarding school system, on Quora:
The amount of time Hermione spends with her parents is actually fairly realistic for boarding school kids in Britain. She goes home for Christmas, and she goes home for part of the summer. She never seems to go home for Easter, which is a bit weird, but neither do any of the other Hogwarts students, so I’m happy to ignore that.
I was not a boarding school kid myself (my school had boarding houses, but the vast majority of pupils were day girls, particularly by the early 2000s when I was in the fifth and sixth forms) but I went to university with a lot of them, have worked with several and shared a room with one for a fortnight at a summer school.
Boarding school kids frequently don’t live near their friends, but are isolated from the kids who live near them because those children do tend to go to school together, or where they don’t they can see each other after school and at weekends, and might be members of the same sports clubs. Kids often don’t want to, or simply can’t, maintain a friendship with someone who’s away at school for most of the year and has become one of “them” rather than one of “us”.
As a result of this, particularly by their late teens (bear in mind that the traditional Public Schools have their main intake at 13, not 11) boarding school kids tend to spend their holidays visiting each other. A group of 5 friends with an 8 week holiday may well spend 2 weeks alone with their parents, then just over a week at each person’s house as a group. If someone’s parents are posted overseas, particularly in a hard to reach place, the kid might either spend a fortnight with them then spend the rest of the holiday in less remote places with friends, or not see their parents at all. Some of my friends had parents who lived overseas but had a pied a terre in London; the friend would stay in the pied a terre, with a housekeeper or neighbours keeping a vague eye on them, except when staying with friends from school.
Now, Hermione wiping her parents’ memories? Not necessary and not fair. Our experiences make us who we are, and by wiping someone’s memories you change those experiences and the effect that has (either by making a difference between personality and remembered experience, which is going to mess you up, or by completely changing the person’s personality by changing their remembered experience) is, in my view, nothing short of criminal.
If Death Eaters had looked for Hermione’s parents with a modicum of intelligence they would have found them and killed them, regardless of whether they remembered being Hermione’s parents. By taking away their memories all Hermione accomplished was to get them to leave Britain without having to persuade them to do so and to rob them of knowledge that would have told them to keep their heads down and could potentially have saved their lives. Death Eater incompetence was the Grangers’ best defence, not anything Hermione did.