You don’t try and attract a specific demographic. You just create the space you want and if they also value that space you they will choose to participate. It’s not 2005 there are women on the internet everywhere. Lemmy has a lot of women compared to reddit and mastodon has a decent women userbase as well it feels.
Hexbear is a bad representation of lemmy ignore their demographic polls.
As for actionable steps I think we are doing a good enough job already. The communities here are not toxic. The users are mature and call out sexist stuff when it happens. The only thing we could probably do is host more content that women typically tend to enjoy but that will come with growth of the site and is better done organically.