Spark of Magic — Trista Ann Michaels

Nicholas and Darien had promised their father they would find Rebecca and keep her safe from the warlock who was determined to see her dead. What they never intended was falling in love with her. Rebecca thought dealing with her magical powers was bad enough. Dealing with the identical twin warlocks sent to protect her, as well as her growing attraction to them, was much worse. Until she finds herself the target of the madman who killed her parents. But Sabastian has so much more in store for the threesome, plus a surprise of his own that will shock everyone. It's not just her life at stake anymore, it's the fate of her entire world and she'll have to learn how to better use her powers before it's too late.