It’s most probable that Rowling is actually trans, but refuses to accept it.

I’ve heard this speculated extensively. It would certainly be ironic.

But I’m more prone to believe she’s one more British Fascist, poisoned by money and a growing circle of reactionary hysterics.

She has even said that she wished she was a boy

A lot of that stems from British entrenched misogyny. Wanting the privileges of masculinity, as much as the actual biology.