Thief of My Heart (Hearts of Stoneleigh Manor #2)
Karla Kratovil

Emma Whittingham is leading a double life. Her father's suicide leaves her to care for her five younger siblings alone. Her estranged uncle is in no financial position to be their guardian, but he does teach her his only skill, how to be a jewel thief.
The trouble is, she can't seem to stay away from the sexy duke. Each time she visits him under cover of darkness is another chance he will figure out her real identity. Then one job goes terribly wrong, and she must ask for help from the only man powerful enough to protect her and her family from ruin.