Full of Grace by Dorothea Benton Frank

The move from New Jersey to Hilton Head, South Carolina, wasn't easy for the Russo family—difficult enough for Big Al and Connie, but even harder for their daughter Maria Graziella, who insists on being called Grace. At thirty-one and still, shockingly, unmarried, Grace has scandalized her staunchly traditional Italian family by moving in with her boyfriend Michael—who, though a truly great guy, is agnostic, commitment-phobic, a scientist, and (horror of horrors) Irish!

Grace adores her parents even though they drive her crazy—and she knows they'd love Michael if they got to know him, but Big Al won't let him into their house. And so the stage is set for a major showdown—which, along with a devastating, unexpected crisis and, perhaps, a miracle or two, just might change Grace's outlook on love, family, and her new life in the new South.