This may be illegal in California. Discrimination on the basis of sex for events open to the public is forbidden. It’s quite broadly construed too, for example bars can’t legally have ladies night.<p>Edit:
To clarify, a nonprofit women’s forum appears fine, but turning it into a business not so much.<p><a href="https://en.m.wikipedia.org/wiki/Unruh_Civil_Rights_Act" rel="nofollow">https://en.m.wikipedia.org/wiki/Unruh_Civil_Rights_Act</a>