I was on the thread on BBC pronouns and started wondering about this. Where I live most secondary schools are single sex. They have strict uniform requirements i.e. the girls have to wear skirts, no trousers allowed.
What would happen if e.g. a girl transitioned? Surely she wouldn't be allowed to move to the boys' school as her sex hasn't changed, but would she be expected to continue living as a boy in a girls' school? Would she be expected to use the girls' toilets and wear skirts?
Same for boys. If a boy transitioned would they be allowed into a girls' school and allowed to wear skirts and use the female toilets, for example?