J is for Judgment (1993) written by Sue Grafton

July 1984 contains two surprises for Kinsey Millhone in the tenth of the 'Alphabet' murder series, both connected to her past. First, California Fedelity Insurance reappears in her life in the form of Mac Voorhies, who wants her help with a case some seven months after his boss Gordon Titus terminated Kinsey's loose employment relationship with CFI. Secondly, in the course of the investigation, Kinsey makes a shocking discovery about her own past when she discovers she has a family she knew nothing about.