City of Fortune by Victoria Thompson

When a day at the races reveals sabotage and subterfuge, Elizabeth Miles must use every ounce of her craftiness to even the score in this all-new Counterfeit Lady novel from USA Today bestselling author Victoria Thompson.
Wealthy but uncouth Sebastian Nolan has invited his lawyer, Gideon Bates, and his lovely new wife, Elizabeth, to attend the famous Belmont Stakes. Nolan is anxious for Gideon and Elizabeth to help his daughter, Irene, acquire a bit of polish, now that his venture into thoroughbred racing has allowed them entry into society. He is also hoping to find her a rich potential suitor. Elizabeth is not exactly the society girl Nolan believes her to be, but she is eager to attend the races. Her con artist family has made a lot of money at racetracks, although not from betting on the horses, and she enjoys the excitement of the track.
Irene Nolan seems more interested in horses than husbands, and she jumps at the chance to show Elizabeth her horse,...