I wonder whether @jk_rowling has given even a moment's thought to the trans boys or young men, many of them acutely vulnerable, whose gender identity she denies, who she belittles,
This is such a privileged standpoint.
She hasn't belittled anyone's identity. I think all she has done is assert that sex based rights are important and that sex based rights can't exist if you can't recognise sex. Throughout history and in many parts of the world today, woman have not been able to escaped sex based restrictions simply by claiming a different identity.
It's ridiculous to pretend that menstruation could happen to anyone, when we know that women's rights are restricted because they menstruate.
As far as I know JK Rowling describes herself as a practising Christian, yet millions of people of other faiths and no faith are able to read her books without feeling attacked.