Her death was announced Monday by St. Thomas' Hospital in London, where she had been treated for the chronic disease for more than five years, and by her husband, Ross Vodden. Britain's Press Assn. said she died Sept. 22.
Hospital officials said they could not confirm the day of her death.
Vodden's connection to the Beatles dates to her early days, when she made friends with schoolmate Julian Lennon, John Lennon's son.
Julian Lennon, then 4 years old, came home from school with a drawing one day, showed it to his father, and said it was "Lucy in the sky with diamonds."
At the time, the Beatles were preparing material for "Sgt. Pepper's Lonely Hearts Club Band," a landmark album released to worldwide acclaim in 1967.
The elder Lennon seized on the image and developed it into what is widely regarded as a psychedelic masterpiece, replete with haunting images of "newspaper taxis" and a "girl with kaleidoscope eyes."
Rock music critics thought the song's title was a veiled reference to LSD, but John Lennon always claimed the phrase came from his son, not from a desire to spell out the initials LSD in code.
Vodden lost touch with Julian Lennon after he left the school following his parents' divorce, but they were reunited in recent years when Julian Lennon, who lives in France, tried to help her cope with the disease.
He sent her flowers and vouchers for use at a gardening center near her home in Surrey in southeast England, and frequently sent her text messages in an effort to boost her spirits.
"I wasn't sure at first how to approach her," Julian Lennon told the Associated Press in June. "I wanted at least to get a note to her. Then I heard she had a great love of gardening, and I thought I'd help with something she's passionate about, and I love gardening too. I wanted to do something to put a smile on her face."
Vodden enjoyed her connection to the Beatles but was not particularly fond of "Lucy in the Sky with Diamonds."
"I don't relate to the song, to that type of song," she told the AP in June. "As a teenager, I made the mistake of telling a couple of friends at school that I was the Lucy in the song and they said, 'No, it's not you; my parents said it's about drugs.' And I didn't know what LSD was at the time, so I just kept it quiet, to myself."