A Wicked Earl's Widow — Aubrey Wynne

Eliza is forced into marriage with no idea her life will change for the better. Married less than a year, her unwilling rake of a husband is surprisingly kind to her -- until his sudden death. The widowed Countess of Sunderland remains under her in-laws' protection to raise her newborn daughter. But her abusive father is on the brink of financial ruin and has plans for another wedding.
Nathaniel, Viscount of Pendleton, gains his title at the age of 12. His kindly but shrewd estate manager becomes father and mentor, instilling in the boy an astute sense of responsibility and compassion for his tenants. Fifteen years later, his family urges him to visit London and seek a wife. The ideal doesn't appeal to him, but his sense of duty tells him it is the next logical step.
Lord Pendleton stumbles upon Eliza on the road, defending an elderly woman against ruffians. After rescuing the exquisite damsel in distress, he finds himself smitten. But Nate soon realizes he must discover the dark secrets of her past to truly save the woman he loves.
A sweet Regency.