Award-winning Kirsty Howard, nine, who was born with her heart back to front, is fighting back after being put on a life support machine.
Kirsty met the queen at the Commonwealth Games
Susie Mathis, fundraiser for Francis House Children's Hospice appeal, said Kirsty, from Manchester, was breathing unaided on Sunday.
She is being treated in the Royal Manchester Children's Hospital.
Ms Mathis said: "She is doing what Kirsty does - fight. She has outlived her medical prognosis for five years."
Kirsty, who was the first child to win the Helen Rollason Award for outstanding courage and achievement in the face of adversity, has fronted campaigns to raise millions for Francis House.
She received the award at the last BBC Sports Personality of the Year Awards.
Kirsty also helped David Beckham give the Jubilee baton to the Queen at the Commonwealth Games in Manchester.
She first came to national prominence when, holding Beckham's hand, she led out the England team at Old Trafford for the 2001 World Cup qualifier against Greece.
Kirsty also helped Victoria Beckham open the 2002 New Year sale at London department store Harrods.