In May 2007 Cathy was diagnosed with a brain tumor after
The Saddle Club (2001) was picked up for Season 3. She had the first of two brain tumours she would suffer from throughout her life removed and underwent radiotherapy treatment at Melbourne Hospital. She was unable to work for multiple years due to the illness. She was diagnosed with another brain tumour in January 2018 and was told would be terminal. Cathy lost her battle with brain cancer on May 4, 2018, more than a decade after she was first diagnosed with the disease. Her death comes six months after her mother, Australian television giant
Rosemary Margan, died also from cancer on the Gold Coast in December 2017 at the age of 80. Rosemary, a champion water skier and three-time Logie winner, was diagnosed with cancer 17 years prior to her death. Ms Browne, who went to visit Cathy daily in hospital in the weeks leading up to her death, said the actress suffered a seizure in recent weeks that left her brain significantly affected.