Rona Newton-John, Olivia Newton-John’s older sister, died Friday in Los Angeles. She was 70.
The English-born Australian actress and singer was diagnosed with brain cancer in April
"My beautiful sister Rona sadly passed," Olivia Newton-John wrote on her Facebook page on Wednesday. "Rona died of a very aggressive brain tumor and mercifully suffered no pain. She was surrounded by the love of her four children - Fiona, Brett,Tottie and Emerson and, her wonderful friends."
"I will miss her forever - my beautiful, smart, talented, funny, brave sister Rona," the 64-year-old actress added.
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Having battled cancer just 20 years ago, Olivia Newton-John had always been supportive of her sister, postponing a Las Vegas show to be with her in April, notes ABC News.
"As a cancer 'thriver' myself, as many people are, I am very aware of the importance of love, support and family during this journey she is about to begin," Newton-John said when she first shared her sister's diagnosis last month.
Olivia Newton-John is best known for her starring role in the 1978 film adaptation of the Broadway musical "Grease," where she played opposite John Travolta. The film's soundtrack went on to become one of the most successful film soundtracks in Hollywood history.
Rona Newton-John was also an actress and married to "Grease" co-star Jeff Conaway from 1980 to 1985.
Conaway died in 2011 from complications related to pneumonia and a degenerative brain condition. During their five-year marriage, the couple had a son, Emmerson, 38, who is presently a race car driver.
Rona later married Brian Goldsmith, a Melbourne restaurant and nightclub owner.
In her younger years, Rona Newton-John was a model and actress, who had a recurring role on the internationally popular British comedy series "The Benny Hill Show."
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Before her death, Rona Newton John had been working for several years on a memoir – "The Dark Side of Charisma." The book was set to be released this summer.
According to Olivia Newton John, a brain tumor wellness program will be started in Rona’s name at the Olivia Newton John Cancer & Wellness Centre in the near future.
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