Can you support alternate forms of identity verification? I'd like to join, but I don't have a Facebook account.
lobste.rs has a invite system where a person who invites someone may potentially be kicked if the person they invite is a problem. See https://lobste.rs/about#invitations
Organize a booth or representative at women-focused tech events like FFC or GHC, or have events/meetups for Leap members to meet face-to-face where prospective members are also invited. The invite system would make this easier to implement.