I'm no historian, so it's a general impression based on things I've read. Doubtless there were "men only" rooms in many places earlier than that, but women seem to have been generally accepted in pubs otherwise. Try to get hold of a copy of Ginette Dunn's book; Part 1 Chapter 2, The Women, is particularly useful on that topic; though it deals specifically with a local Suffolk tradition and with people who were born no earlier than the 1880s, much it would extrapolate to other situations, I would think.