I read this and had to respond: of course it's not "both". Sex is denoted by chromosome supply and deployment, but gender is a matter of mental orientation. From whatever cause.

I do realize this must be very old stuff to lots of people, but the fact is I never had occasion to think about it before.

(It occurs to me I do have sort of a mental-homecoming story already in the works, but I think it'd have to be replotted too much in making the sex more of the narrative. Oh well.)