Linuxchix is a looseknit organization, and its local chapters which, like the mother organization, are completely unofficial tend to be looseknit, casual groups, too.
Most chapters are for regional groups so that they can meet or organise local chix events. However, you could also found a special interest chapter, or a language based chapter (such as a global, French language, chapter).
Local Linuxchix chapters are completely autonomous provided that your chapter observes the central aim of LinuxChix: supporting women in Linux, and your chapter observes the be polite, be helpful rules. You can do anything you like beyond that.