What the Duke Doesn't Know (The Sinclairs - Book 1) by Isabella Ward-Whiteley

A lady of rank, they say, is known by three things: the calm of her hands, the height of her pedigree, and the depth of her purse. Delia Fairfax can lay claim to only one - and she has learned never to take off her gloves. Ever since her father gambled away the Barony of Fairfax stone by stone and card by card, Delia has kept her mother and two sisters afloat on wit, pride, and a great many carefully guarded secrets. So when a dangerous bargain draws her into the orbit of a formidable Sinclair duke, she sees at last a way to secure her family's future - on one condition: he must never discover the truth about who she really is, or what she has done to survive. But the Duke is far too clever, far too watchful, and far too tempting for her peace of mind, and every stolen moment carries her closer to the one revelation that could ruin them both. A sparkling and emotional Regency romance brimming with secrets, sharp wit, and slow-burning desire. Book 1 of 'The Sinclairs'.