Not Quite a Lady

At seventeen, and reckoned a complete nobody—certainly not quite a lady—Angel has nonetheless charmed the whole of London society with her gamine graces. But what is she doing as the ward of mad Matt Vail, the dashing hero of the recent French campaign?   
Impulsively rescued by Matt from the evil intentions of his black-hearted cousin Martin, Angel quite frankly adores him. But to win his love, she has to seduce him from the worship of his long-dead sweetheart and his very live mistress.