I went to an all girls school, and have a dd at a girls school now.
My schooling encompassed everything, from food tech and textiles to car mechanics and outdoor pursuits, with everything in between. There truly were no limits.
My dd is at a similar school now. She did ask why I wanted her in a single sex secondary (she was at a mixed prep), and I talked it through with her. I’m not sure she was fully on board with my reasoning before she went, but loved the school, and was happy to agree to go there.
Now she has been there a year, she regularly comments how much more relaxed, how much freer, it is. She is loving it - both the opportunity to ‘speak up’ and find herself (she was very quiet at her mixed prep) and the fact that socially, there are no girls ‘performing’ for the boys (happened at her prep from a very young age) and so that entire subset of skewed interaction is missing, which she sees as a huge positive.
There are, of course, opportunities to mix with local boys/mixed schools, and opportunities out of school too. She is in now way in a single sex bubble, never coming across boys/males at all. She does have a space where she is free from the social pressures (which start so very young and are ingrained, and this is now a chance to undo some of that damage) to perform femininity, she is no longer (as a well behaved, quiet girl) used to try to quieten down the loud boys in ridiculous classroom management techniques, and she is loving every minute of it.