Hayley Okines, who bravely fought premature ageing disease progeria, has died aged 17.
Her mother Kerry Okines posted on Facebook: "My baby girl has gone somewhere better. She took her last breath in my arms at 9.39pm x."
Hayley, from Bexhill, East Sussex, suffered from a premature ageing disease called progeria.
Doctors said she wouldn't live past the age of 13. But she was a fighter and at the age of 14 published her autobiography called Old Before my Time.
The incurable disorder ages her eight times faster than normal, and Hayley who was 17, was left with a 104-year-old’s body.
There are only around 50 known cases of the condition on the planet.
Earlier this week her mother, Kerry posted an update to Facebook explaining Hayley was suffering from pneumonia.