It supports the families of youngsters who cannot breathe independently.
Founder, Victoria Townsend, said: “We are so proud of George.
“There was a rule of no under-11s in case children became restless. But they made an exception for George because he is representing Stephen’s charity.”
The schoolboy met British astronaut Tim Peake and Sherlock star Benedict Cumberbatch at Westminster Abbey after travelling first-class for free with Richard Branson’s Virgin East Coast Railway and meeting his train’s driver.
However, the youngster would not have been at the service at all but for mother Hollie, a student nurse, and gran Nicola who refused to listen when doctors said he had no hope of survival when born.
The pair fought to have him transferred from hospital in Leeds to Newcastle upon Tyne where heart surgeons have carried out 15 major operations.
He was given days to live at one stage and had 15 hours of surgery on his first birthday.
Like Prof Hawking, George has a tracheotomy – an incision in the windpipe – to help him breath. He is also fitted with a pacemaker, has a feeding tube and is on oxygen every night.
The youngster, from Skipton, North Yorkshire, was born with a rare condition where the pulmonary artery and aorta are the wrong way around. It also affects his eight-year-old brother Harvey.
Gran Nicola Garbutt, 48, said: “George is an amazing child who lives life to the full despite having to have a tube in the throat and needing oxygen. “And to think the doctors in Leeds just wanted us to take him home to die.”