Berg's lovely novels examine how some families grasp blindly at the ties that hold them together and some pluck them apart. Mending is no exception. When Laura's father becomes ill, her sister Caroline confronts her and their brother, Steve, with an unpleasant revelation: She was abused by their mother throughout her childhood. So the siblings sort through their complicated family history (''How could the mother I had be the mother who did such things?'' Laura wonders), mourn their father's death, and deal with their still-manipulative mother. Though it's not Berg's best effort, book clubs should have a ball with this solid little novel.