Sense and Sensibility
We're sure that Mrs. Jennings would get a kick out of seeing herself described as a "Guide" or "Mentor." She certainly likes to think of herself as a guiding light to Elinor and Marianne, and she takes her responsibility to them very seriously (albeit oddly, at times). Mrs. Jennings doesn't actually manage to instill any elements of her personality in Elinor or Marianne, but she does serve as a kind of means to the novel's end – without her intervention in bringing the girls to London, we wouldn't see what's going on with all of the various plots, and we might never arrive at the neatly tied-up ending that we eventually receive. Mrs. Jennings is a kind of surrogate mother, who indulgently gives Elinor and Marianne the space to develop into their own individual people, not just members of the Dashwood family, while they're in London.