Devil's Daughter

Once more, I highly recommend to Lisa Kleypas books... Here you can find:
A young widow, mother of two, somewhat depressed...
A former dissolute rake, that learned to live healthy doing a great job in “high agriculture”, being the trust man of a rising family empire/fortune...
Our hero, a “diamond” torment by demons who find love in the arms of a damsel in distress... Asked to help, he run to uncover the wrongdoings of her husband cousin and lived a hot relationship but persist in not seeing his true value.
But... An intelligent to be father in law willing to give to that poor soul an hand and finally our alpha hero and his true love overcome the last obstacle to found happiness... to marry and have their forevermore love...