Join the Mercury News' Katy Murphy in the aftermath of the suicide of Saratoga High School sophomore Audrie Pott as she leads a discussion with Rebecca Rialon Berry, a child psychologist from the Lucile Packard Children's Hospital at Stanford. They will talk about ways parents can recognize that their child has experienced a traumatic event, and how to help manage their child's social media/online presence. The chat will take place at 5:45 p.m. April 15.