Setting a password is not necessary to restrict access. Instead create user groups "men" and "women" (OPTIONS > USERS > MANAGE USERS & GROUPS) and assign your registered users to the appropriate group, then set permissions to restrict access according to their group.
You can make the inappropriate folder invisible to members of those groups that should not see it (OPTIONS > USERS > CHANGE PERMISSIONS), or merely prevent them from posting. It is even possible to allow "anyone" or "registered" users to see that the male and female folders exist (but not allow them access), but once the user is assigned a gender then to make the other folder invisible.
Volunteer Helper - but recommending that users move off the platform!
Once the admin for GregHelp now deleted.