The Clever Strumpet by Merry Farmer

Passion is its own reward…
Lady Caroline Pepys has taken matters into her own hands. Now that she is mistress of the school for young ladies with ruined reputations, she plans not only to give her friends the tools they will need to survive in a hostile world, she intends to claim the hand of the rakish Lord Rufus Herrington for herself. But first she plans to recover the missing Chandramukhi Diamond and bring its thief to justice.
Rufus has never fallen so head-over-heels in love with a woman in his life, and he will stop at nothing to help Caro in her quest to recover the diamond. But with pressure mounting for him to marry in order to restore his family’s fortunes, will his dalliance with Caro be his last affair before a lifetime of misery or will he and Caro find a way for love to conquer all?