A Clutter of Cats (A Maples Mystery #5) by Louise Carson

It's late spring and young artist Gerry Coneybear and her twenty cats are thrilled to finally be able to spend time in the garden surrounding her 200-year-old house on the Ottawa River. But Gerry is having difficulty keeping her curious cats safe from her new neighbours' large dog. The couple's? marriage appears a bit fraught, and when the philandering husband is murdered, the wife is the obvious suspect. Or ought to be. As events unfold next door, Gerry watches from her garden, where she picks rhubarb, weeds, and plants her flowers, catnip and herbs, all supervised by her cats and her friend and part-time housekeeper Prudence. A terrible car crash, an eccentric train engineer (and his equally eccentric wife), and a midnight visit to the house next door all contribute to this cozy mystery coming out all right in the end. And there's jam-making. And ghosts.