Who is Tippy Parsons from 'I' Is for Innocent and what is their importance?

Tippy is Rhe Parsons' daughter. She is also Isabelle's best friend. Tippy started to drink when she was ten-years-old at the urging of a babysitter. It wasn't until Isabelle's murder that she sought help for her addiction. Over the course of the novel, Kinsey learns that Tippy killed an elderly man in a hit and run and encourages her to turn herself in. Tippy does so, despite her mother's fear and outrage. In the end, they learn that the statute of limitations has passed and she will not be charged in the crime.