His to Keep (Regency Scoundrels #2)

Lady Gemma St. Martin rebelled at the thought of having a keeper to guard her every move, but when she met her keeper, the rakishly charming Scotsman, Archie Campbell, her rebellion turned to surrender.
Independent and free spirited, Gemma St. Martin wanted to dictate her fate in life. When she sets her sights on a totally unsuitable husband, however, Mallory St. Martin intervenes, and hires her a keeper—the mysterious Scotsman, Archie Campbell.
Archie loses his heart to Lady Gemma the first time he sets eyes on her and decides to make her his, but a tragic secret connects both families that just might destroy their chances of finding happiness.