One of the most infamous women associates was Virginia Hill who in turn worked as "bagman" for the Mob and also worked as "spy" for the Chicago Outfit.

Also as Furio said, some women in Italy acted as messengers between their imprisoned husbands or brothers, or even sometimes acted as bosses for the organization, again in some "connected" role. Maybe Im wrong and probably both Furio and Strax can correct me, but I think these examples were mainly seen in the Camorra...