Who is Patty Giacomin in the novel, Early Autumn?

Patty Giacomin is the woman who hires Spenser to get her son, Paul, back. Patty says that her ex-husband and Paul's father, Mel, has taken the boy, that the police will subpoena Mel if they can find him, but that the case isn't high on their priority list. When Spenser does retrieve Paul, Patty informs them that she hadn't expected a resolution so soon and has dinner plans, leaving Spenser to take Paul out for dinner as well. Patty makes a play for Spenser and it's later evident that she travels monthly to New York where she gets drunk and has sex with a stranger.