Olivia Newton-John Is Recuperating from Cancer Treatments with Herbs and Cannabis: Source

Olivia Newton John is continuing to stay positive as she faces breast cancer.

Last week, the 70-year-old Grease actress — who announced in 2017 that she had been diagnosed with stage 4 breast cancer that had metastasized to her back — reassured fans that she was doing just fine after tabloid reports circulated claiming she was on her deathbed.

A source close to Newton-John tells PEOPLE in this week’s issue that while the “absurd” reports “scared” her family and friends, she is indeed “doing great” and recuperating from her cancer treatments. Newton-John, a proponent of pairing traditional medicine with holistic wellness methods, has long credited the use of herbs and cannabis with feeling her best.

“That’s a major part of her treatment and recovery,” the source says. “A lot of the reason she’s looking and feeling so great has to do with the holistic stuff she’s doing. She has always been about healing the body, mind and spirit.”

After finishing a recent series of medical treatments in California, the source says Newton-John “took a couple of months off to get herself back to strength” and adds that “she’s going to constantly be going through treatments, but she’s doing well.”

Newton-John was first diagnosed with cancer in 1992 and underwent a partial mastectomy, nine months of chemotherapy and a breast reconstruction. After first beating the disease, Newton-John became an advocate for breast cancer research and early detection.

In May 2017, doctors diagnosed Newton-John with stage 4 breast cancer that had metastasized to the sacrum. The star initially postponed the first half of her concert tour because of severe back pain from what she thought was sciatica, but further tests discovered it was actually cancer that had spread.

Newton-John’s most recent diagnosis is her third bout with cancer, which some doctors describe as incurable but capable of being managed through treatment.

RELATED: Olivia Newton-John Speaks Out After Reports She Has Just Weeks to Live

Last week, RadarOnline claimed that Newton-John’s “bodily functions appear to be shutting down” and that she is “clinging to life” so that she can see her daughter, Chloe Lattanzi, marry her longtime fiancé James Driskill in 2019. The report also claimed Newton-John is spending her “final days” at her home in Santa Barbara with her husband of 10 years, John Easterling.

The report triggered a whirl of rumors on social media and in tabloid reports in Newton-John’s native Australia.

Already planning to post a New Year’s greeting to fans, Newton-John took the chance to clear things up about her health.

“I just want to say the rumors of my death have been greatly exaggerated,” she said, quoting Mark Twain in a video posted to her Instagram account on Jan. 2. “I’m doing great, and I want to wish all of you the happiest, healthiest 2019 that’s possible.”

For the latest on Olivia Newton-John’s health, pick up this week’s issue of PEOPLE on newsstands now.

“Thank you all for the wonderful love and support for me and for my Olivia Newton-John Cancer Wellness Centre in Melbourne, Australia,” she added.

Newton-John’s niece, Tottie Goldsmith, also spoke out on Instagram earlier to clear up the mounting claims about her aunt’s health.

“Just giving you the heads up that Livvy is in good health, so let’s leave that distressing rumor where it belongs,” Goldsmith shared, along with a photo of her posing with Newton-John.

Goldsmith told Australia’s Seven Network that Newton-John had given her permission to speak out about her publicly, and that “you can rest assured she is going nowhere and in really good health. A sick rumor.”

A representative for Newton-John previously told PEOPLE that the reports about her failing health were “ridiculous” and “crap.”

Now gearing up for the U.S. release and book tour for her memoir Don’t Stop Believin’ in March, Newton-John “is vibrant,” says the source. “[Reports] had her 6-feet under, but she’s putting all that to shame.”