Lady of Quality, by Georgette Heyer
Everybody needs a little Georgette Heyer in their lives now and then! This one had been sitting around on my shelves for...probably a year or so, and I picked it up in a fit of "I'm going to read easy books that I can then put in the Little Free Library and clear up some space." I wound up having a lot of fun with it.
Because guess what, this novel is set in Bath! And now I have been to Bath, and I know much better what the Pump Room and Milsom Street look like, and I can have a lot more fun imagining the story.
Miss Annis Wychwood is wealthy and independent, and at 29 has never thought it worth her while to marry. Tired of living with her overbearing (if well-meaning) brother, she has set up her own very respectable household in Bath, complete with irritating elderly cousin as chaperone. Accident brings the sweet but headstrong heiress Lucilla Carleton into Annis' household, and the ensuing chaos -- along with a lot of opinionated relatives -- turns her life upside-down.
Just as much fun as Heyer's Regency stories always are.