A few of you mentioned Janice Lester. Frankly, I'd be just as happy if they just retconned it so that women could always be captain - and Janice couldnt be captain because she was NUTS, not because she was a woman.
after all, we saw women captains in the movies.
I just don't think we've seen enough (if any) women Captains in this universe to prove JL wrong.
In TOS including the movies I remember just one woman captain and that was well after the time of JL.