Mistress of Merrivale by Shelley Munro

Jocelyn Townsend’s life as a courtesan is nothing like the life she envisioned in her girlish dreams. But, at least it allows her and her eccentric mother to live in relative security—until her protector announces his plans for marriage and no longer requires her services.
Desperate to find a new benefactor, one kind enough to accept her mother’s increasingly mad flights of fancy, Jocelyn is uncertain when a lifeline comes from an unexpected source.
Leo Sherbourne’s requirements for a wife are few. She must mother his young daughter, run his household, and warm his bed. All in a calm, dignified manner with a full measure of common sense. After his late wife’s histrionics and infidelity, he craves a simpler, quieter life.
As they embark on their arrangement, Leo and Jocelyn discover an attraction that heats their bedroom and a mutual admiration that warms their days. But it isn’t long before gossip regarding the fate of Leo’s first wife, and his frequent, unexplained absences, make Jocelyn wonder if the secrets of Merrivale Manor are rooted in murder…