Discworld AU where Agnes Nitt joins the City Watch instead of the opera house.
Is immediately taken under the wing of Angua and Cheery, both of whom find themselves relating to her (Angua because of the dual-mind thing, Cheery because of the physicality thing).
Carrot, of course, knew her family already, and they catch up on how things are back in the Ramtops. Carrot mainly asks about shaft four in Copperhead reopening, but Agnes appreciates the thought nonetheless.
Agnes gets on surprisingly well with Nobby Nobbs. Even gives him pointers of make-up.
Sybil takes a personal interest in Agnes's career, and mentions this to Vimes.
Of course, Vimes unintentionally adds her to his rapidly-expanding mental list of adoptive children. Someone makes a fat joke, and Vimes sees the Look on Agnes's face. He immediately recognises it as the same Look that Sybil has whenever a joke like that is made about her. Vimes takes the perpuator aside for a quiet word; within a few hours, the entire city population knows that they Will Not Ever Make That Sort Of Joke Again.
When Granny Weatherwax and Nanny Ogg arrive in the city and head for Pseudopolis Yard, Granny refuses to step into the Watch House. She quietly states that this territory is Someone Else's. Nanny is about to object but sees the look on Granny's face and quietly agrees. Agnes Nitt is left alone to make her own path, whatever that may be.