The Wallflower Wager (Girl Meets Duke #3) by Tessa Dare

For years, Penelope has been taking in every stray animal that has come her way. However, when Gabriel Duke renovates the house next door and realizes that no one would want to buy a house next to Penny's menagerie, he helps her try to find loving homes for her animals. In this process, Penny learns more about Gabriel's past hurts, and there never was a wounded creature that she could turn away.