Celeste Kane (née Carnathan) was first introduced on the Pilot as Duncan's mother, who, when Veronica Mars and Duncan were dating disapproved of their relationship. She decided to tell Duncan that Veronica could have been his half-sister, because of Jake Kane's affair with Lianne Mars. This caused Duncan to break up with Veronica. Before Lilly Kane died, Celeste had shown some resentment towards her daughters' way of life, and blamed every problem her family faced with was on Lilly. In her last appearance, Donut Run, she hired Vinnie Van Lowe to find Duncan. Her plan backfires when she gets the "Vinnie Classic". She gave birth to Lilly in 1988, making her 18 in 2006 & the Lilly Kane Memorial was erected as a tribute to Neptune High.
She is last seen in the film, she shot Weevil when he approached her car to help her when bikers surrounded her. Her divorce from Jake Kane was confirmed when Veronica calls her "the richest divorcee in Southern California"