Lucy O’Donnell was 4 years old when her classmate at nursery painted a picture of her, surrounded it with stars and squiggles and took it home to show his parents.

“It’s Lucy in the sky with diamonds,” Julian Lennon told his father, inspiring one of the Beatles’ most enigmatic songs and carving his friend a slice of musical immortality.

Real life could never match that and yesterday St Thomas’ Hospital, Central London, said the woman the world knew as “the girl with kaleidoscope eyes” had died on holiday in Norfolk after suffering for years from lupus, a vicious disease of the immune system that causes the body to attack its own cells. She was 46.

Lucy in the Sky with Diamonds was written in the midst of the Beatles’ psychedelic period and featured on the Sgt. Pepper’s Lonely Hearts Club Band album in 1967. Its dreamy, hallucinatory lyrics owed more to John Lennon’s favourite writer, Lewis Carroll, than they did to his son’s playmate.

The real Lucy hated the song that she inspired because “I don’t feel I can relate to it. I just don’t like it. I don’t see a four-year-old kid running around with kaleidoscopic eyes. It doesn’t make sense.”

She met Julian in Weybridge, Surrey, where the family recall he would be dropped off at Heath House nursery school in a Rolls-Royce. She went to St Maur's school in Weybridge, college in Guildford and later moved to Surbiton.

The little blonde girl in Julian Lennon’s watercolour sketch grew up with a love of children. Illness prevented her having her own, but she studied nursery nursing and worked with special needs children, running a specialist nanny agency until she began to suffer from the autoimmune diseases psoriasis and lupus in her thirties.

She married her childhood sweetheart, Ross Vodden, in 1996, and Julian Lennon, whom she had seen only once since their nursery days, sent a note to the wedding.

The Voddens were two days into their first holiday in eight years when Lucy developed an infection and was taken to hospital in King’s Lynn, where she died last Tuesday with her husband and family at her bedside, including her father, the writer and doctor Michael O’Donnell. Her elder sister, Fran, said: “She had been so excited about the holiday that she drove herself half the way there, which is incredible, but she got the infection and with no immune system there was absolutely no chance of her beating it at all.

“She is utterly irreplaceable in my life and I have a nine-year-old son who thinks his life is over without her in it. I have had hundreds of e-mails and every single one says they all remember her smiling and laughing.”

Angie Davidson, campaign director of the St Thomas’ Lupus Trust, which had been supporting Mr and Mrs Vodden during her illness, said: “It’s so sad that she has finally lost the battle she fought so bravely for so long. She was a real fighter and she didn’t let it take her over. She was very outgoing, a very bubbly, fun person.”

Ms Davidson said Julian Lennon and his mother, Cynthia, were “shocked and saddened” by her death.

The former classmates had resumed their friendship in recent months after Lennon, who lives in France, heard she was ill. “I’ve been able to help out a bit,” he said earlier this year. “I was so upset to hear what had happened.”

“It was lovely of Julian,” Mrs Vodden said at the time. “We were two very energetic school kids. He would say, ‘Come on, Lucy’, to get me to do things. He was the bravest boy in school.”

The whereabouts of Lennon’s sketch are unknown. The song it inspired will not be played at the funeral.

More information about lupus can be found at the St Thomas’ Lupus Trust’s website

With a little help from . . . . the names behind the songs

• Originally Hey Jules, Hey Jude was written by Paul McCartney to console Julian Lennon after his parents John and Cynthia separated

• Eric Clapton based Layla on a 12th-century Persian story of unrequited love that mirrored his desire for Pattie Boyd, the wife of George Harrison. They divorced in 1977, she married Clapton in 1979

• Sweet Caroline was inspired by John F. Kennedy’s young daughter, Caroline. While sitting in a Memphis hotel room, Neil Diamond saw a picture of her horseriding

• When the drummer Jerry Allison broke up with his girlfriend Peggy Sue Gerron, Buddy Holly and the Crickets reworked an existing song, Cindy Lou, which was originally about Buddy Holly’s niece

• Chuck Berry’s piano player, Johnnie Johnson, may be behind the title of his 1955 song. If Johnson had too many drinks, Berry would apparently say Johnny B. Goode

• Neither Paul Simon nor Art Garfunkel have revealed the identity of Cecilia, but a popular theory remains that it was Simon’s dog

Editor's choice

• The 100 Best Films of the Decade
• 70 facts you didn't know about Marvel
• The 50 Biggest Movies Of 2010