Dangerous Relations — Marilyn Levinson

After Ardin Wesley's cousin Suziette is murdered, her widower, Brett, asks Ardin to help him adopt Suziette's little girl, whom he's grown to love. Trouble is, no one knows the identity of the child's natural father. Ardin decides she wants to adopt Leonie, and take her to home to Manhattan.
Although she is drawn to Brett, an abusive husband turned Ardin against love and marriage. Brett feels betrayed when he learns of her plans to adopt the child. When someone sets fire to Ardin's aunt's house, she barely escapes with her life. Despite their differences, Brett offers her shelter and together they work to create a secure home for the bereft little girl and to discover the identity of her father before someone else dies to protect his terrible secret.