I'm building my own imageboard and I'm determined that it won't be a sausage-fest. I'm going to go out on a limb here & say that 8chan, 4chan, etc probably are, for the most part. Why else would there be a catch-all board like /fem/ specifically for women? Ideally there should be a whole bunch of specialized boards that cater to womens interests.
What other boards are there that are frequented mostly by women?