In Her Skin (also known as I Am You from the working title How to Change in 9 Weeks) is a 2009 Australian drama movie written and directed by Simone North. The film is based on the true story of the murder of 15-year-old Rachel Barber, Ivan Southall's granddaughter, who went missing on March 1, 1999. It was later discovered that Barber was murdered by a former neighbour and family babysitter, Caroline Reed Robertson.

The film's story is told from alternating points of view; the victim, the victim's parents, and the murderer. Flashbacks reveal details about all of the characters, including the motive of the murderer. In Her Skin is inspired by the book Perfect Victim by Elizabeth Southall (Rachel's mother) and Megan Norris (an Investigative reporter).