Witch - The Gail Sommers Trilogy, #1

Learn their secrets. Gail Sommers doesn't know who placed the curse on her family. All she knows is that the lives of everyone she loves are in grave danger if she stays in New York City. For once in her life, Gail's stubbornness is her strength. She'll leave town in the dead of night, without a word to her family, her friends, or her lover Michael.  She'll find the source of the curse, and she'll destroy it.
She doesn't care who gets in her way. The Tír Uaighe gang is close on her heels, and she doesn't entirely know how to be a witch yet. But that doesn't matter.  Because now, it's not just about Gail. It's about her baby. And nothing pisses a witch off more than someone threatening her family.