From what ive read it seems that with all the men in prison they have to put someone experienced in charge.so the persons who have the required experience and are bound to the omerta are sometimes women.not that there are whole clans with only women,but im sure.that the cosa nostra also had some females in charge.
there are few books about that subject in english. if you ar interested i could upload this book. http://link.springer.com/book/10.1007/978-0-387-36542-8/page/1