The Nesting Dolls by Gail Bowen

Joanne Kilbourn's Christmas holidays are disrupted when a woman hands a baby to her daughter's best friend, Isobel, telling her that the baby belongs with Isobel's mother, Delia. Delia is a lifelong friend and law partner of Joanne's husband, Zack Shreve. The disappearing mother is discovered to be Delia's daughter, Abby, whom she gave up for adoption at birth. When Abby is then found murdered, Joanne and Zack are embroiled even deeper in the mystery of who Abby was, who would want her dead, and the fight for who should have custody of her son, Jacob. In The Nesting Dolls, Bowen has again crafted a novel revolving around her family and life in Regina, Saskatchewan.