Was the women vote for the Republicans back then due to being the party of women rights and the Dems being the backwards party?
Probably.
You have to remember that back in the late 1950's-early 1960's a lot of the Democratic party faithful were White Southern Males and Catholics. Both groups that had quite the chauvinistic streak. Meanwhile, the Republican Party at the time had been putting the Equal Rights Amendment (ERA) on the party platform since the 1940's (at least).
So yeah, something to that effect.