A Dragon's Heart, The Dragon Queen Series

Left at the altar, Mia DiMarco's perfect world comes crashing down.
Hurt and angry, she retreats to the only place she's ever felt safe in this foreign land, the castle where she works.
It is there, that a fervent wish launches her back in time to Napoleonic France, where war rages.
Mia will have to face history in her present with a man she's only ever read about -- Lord Greyson Dumont-- who sets heart her on fire. The problem is, she also knows he is destined to die.
She'll do anything to change history, even if it means sacrificing her mortal heart to the powerful dragon.