The Lady and the Lost Heir by Katy Baker

He wasn’t expecting a title, or to fall in love.
Miranda, Lady Madeley, was married at eighteen to Sir Geoffrey Madeley, a man far older than her. He left her a young widow with three growing daughters who are all much keener on their horses than on meeting suitable gentlemen. Unfortunately, Sir Geoffrey neglected to provide for his family in his will, and his dutiful solicitor has discovered a distant cousin who is to inherit his title, the Windrush estate, and even the inheritance Miranda herself brought to the marriage. She’s left with just an old farmhouse.

Captain Harry Madeley, late of Wellington’s army and veteran of Waterloo, where he was an army doctor, has no idea there’s a title of any sort in his father’s family. He’s been badly wounded and is very much in recovery—in no condition to run a country estate. However, he decides to go and see what he’s so unexpectedly inherited. He learns Sir Geoffrey’s widow has vacated Windrush, a house far bigger than any he’s ever known.

Soon enough, he encounters the youngest of her strong-willed daughters and is invited back to the farmhouse, where he discovers Lady Madeley is anything but the woman he was expecting. Miranda, upon finding out the lost heir is not married, determines to engineer a match between him and her oldest. However, her daughters have other ideas.