As the story goes, one day Lennon was picking Julian up from nursery when his son showed him a picture he had drawn of a girl surrounded by starlike shapes.
His father then used the image as the inspiration for the song that features on Sgt Pepper's Lonely Hearts Club Band, released in 1967.
But according to Julian, Lucy, now 46 and Mrs Vodden after marriage, is suffering from the chronic auto-immune disease where the body's defence system begins to attack itself, causing damage in joints and organs.
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