Leak was born in Cardiff, Wales on September 28, 1947. She made her debut in front of the camera in 1966 with a guest appearance in the series “Wojeck”. In 1968, she starred in the comedy “Yours, Mine and Ours”. It was about a widower with ten children who marries a widow with eight children. Together they try to survive while raising eighteen children.
In the following years, Leak appeared mainly in soap operas. She appeared, among others, in “The Heat of Youth” and “Another World”. In the mid-1980s, she took a break from acting. Her last role was a guest appearance on the TV series “Loving” in 1992. After ending her acting career, she worked as a real estate agent.
For seven years, Leak had been struggling with progressive supranuclear palsy, a rare disease of the nervous system whose symptoms resemble Parkinson's syndrome and dementia. She died at her home in Jupiter, Florida.
The actress was said goodbye to, among others, her ex-husband Tim Matheson, whom she met on the set of “Yours, Mine and Ours”. “It is with a heavy heart that I announce the passing of Jennifer Leak. She was not only my on-screen sister in 'Yours, Mine and Ours', but also my beloved first wife. She was a special woman, strong, full of love and incredibly talented. My deepest condolences to James D. 'Auria, her husband of 47 years, and her many loved ones,' Matheson wrote in a Facebook post.