I wonder to what extent that is due to women being discriminated against after they apply, or women being less likely to apply. If there is a significant difference in the acceptance rate, they should consider concealing characteristics like gender as much as possible in the process and maybe inviting people with more diverse perspectives to assess candidates. If there is no significant difference, they should consider advertising YC places where they may reach a different audience and publish statistics that reassure applicants that they will be treated equally.