Hell yeah! I named the Head Honcho of the gang Springheel Jack :) I consider myself to be a font of genuiosity.

But yeah, the interaction between them and Mary is something that can make for a hell of a good story. I've only written it from Holmes perspective and in the abstract, but can;t you just see him growing increasingly bitter as she makes inroads among them as well? Gets them to bring lunches for Watson and Holmes when they are on cases? Start explaining the basic personal hygiene? Scandalize her neighbours by essentially becoming a surrogate mother to the entire mob... :)