There are a lot of weirdnesses on this thread.
There shouldn’t be any sexual assault in a school, ever. If there is, and, of course, it has happened, that would be a serious matter for the school. A lot of the sexual assault and, more commonly, sexual bullying, takes place either online or not in school hours. ‘Everyone’s invited’ contained plenty of stories from girls at single sex schools who tended to mix with the opposite sex school at parties etc.
OTOH, I honestly do feel that the girls were far more relaxed at the girls’ school where I taught than the mixed school and, in lessons (I taught Physics), were far more likely to take risks in asking questions and say when they didn’t understand. About 80% of girls chose to stay on to the sixth form when they had the choice (it was a wealthy private school so most had the option to move).
But, for the 20% of girls who chose to move, a lot cited the pressure cooker environment of girls’ friendship groups and felt boys would dilute this.
In my personal opinion, single sex education for girls is a good option and if I had daughters (I have sons) I think I would choose it. It is a lot to cope with hormones, first relationships. social media and academic pressure all at the same time. For the majority of girls I do think a single sex school is a safe space (hate the term) where they can just focus on academics, sports and other cocurricular activities, and they can meet boys after school and weekends and holidays.
Of course it doesn’t mimic a real world workplace and there will be a transition to a university or work place environment, but I feel that hopefully maturity and confidence will already have been gained by then.
And finally, as I have already said, it is horses for courses. We should have all types of school: private, state, single sex, coed, academic, mixed ability, relaxed, strict etc etc. Reducing choice is never a good thing.