The laundry-verse pivots from Peter Pan to Mary Poppins, with a nod to (among others) D&D, the Teletubbies, American creationist-adjacent museums, muppets (no, not the Muppets), Power Pack, and possibly the Blue Fairy from Pinocchio
At one point Mary the supervillain nanny reaches into her magic bag for something that would stop a T rex (which is coming through as the "walls" thin around the museum; she pulls out an anti tank weapon from her magic handbag