Everything You Have Is Mine

Description for EVERYTHING YOU HAVE IS MINE by Sandra Scoppettone:

Lauren Laurano is surely not the first gay P.I. in New York City, but she is in a class by herself. Smart, stylish, and self-determined, she lives with her longtime lover, Kip, in a Greenwich Village brownstone. Their lives together usually simmer along nicely -- except when Lauren becomes obsessed with a case.

Lovely, shy Lake Huron has been raped and refuses to talk to the police. Her older half-sister, Ursula, brings in Lauren, who seems to win the young woman's trust. But before she can tell Lauren everything, Lake is found dead, leaving Lauren to decipher a 21st-century clue and a dysfunctional family tree that a good, stiff wind could blow to bits. The closer Lauren gets to the truth, the more her own life is endangered -- by a past that can't stay buried and fragile questions that have no easy answers....

This is #1 in A Lauren Laurano Mystery.