The daughter of Olivia Newton-John says she has "not been okay" since her mother's death last year.
Newton-John, a British-born actress and singer who grew up in Australia, died in August last year at the age of 73.
She is best known for playing Sandy opposite John Travolta in the 1978 hit musical film Grease.
Her daughter Chloe Rose Lattanzi, also an actress and singer, appeared to suggest to her followers in an Instagram video that she needed a month-long break from working to recover.
She said: "Since my mom’s passing, and the year and a half, with her going through cancer, I have not been okay.
"If I have forgotten to return your calls… I’ve had extreme memory loss. I’ve had difficulty getting out of bed. I’ve stuck to my commitments, but I’ve been neglecting myself.
"One of my mom’s biggest messages was take care of you. If you don’t take care of you, you cannot give your full capacity of love, wisdom, kindness, and power to everyone else.
"So, after the walk, I’m going to disappear for about three weeks, just to honour my mind, body and spirit, because I’m developing a little bit of health issues in my mind and my body.
"And I just wanted to say to anyone who I have been inconsistent with, I’m so sorry, I haven’t been consistent with myself, and I haven’t been taken care of myself.
"So, in the spirit of my mother and the spirit of the wellness walk, I’m going to take a month to do that so I can be of complete service to everyone else."
Lattanzi, 37, is the daughter of Newton-John and her former husband Matt Lattanzi, whom the actress divorced in 1995.
In 2008, Newton-John married her second husband, businessman and conservationist John Easterling, and they remained married until her death.
She died "peacefully" at her ranch in southern California, surrounded by family and friends.
Stars such as Dolly Parton, Elton John and Mariah Carey were among those who paid tribute to the "beautiful and courageous" actress and singer and a state memorial service in Australia was held.
Source: Press Association
