I think most villainess stories already target the female audience rather than the male one. Not to mention the shōjo genre, I mean there are probably a lot of women who read comics, like a lot. So I don't see why they wouldn't read on MangaDex either.
Most english literature (romans) is written for women nowadays anyway. I know comics are probably different, but it's a fact, there are way more women who often read and buy than men (english coutries at least, I don't have data for other developped countries). This statistic is probably above average in most countries too.