The Duke of Sussex also paid a special tribute to Scarlett, a 10-year-old girl who helps with the care of her sister Freya.
Prince Harry said: 'Scarlett, who has been sitting next to me while we have been watching these remarkably inspirational stories this evening, is an absolutely perfect example of exactly that why training for families is so incredibly important.
'At 10 years old, she plays a key role in caring for her sister Freya – and I know that there have been occasions when she has taken the lead in managing Freya’s feeding and oxygen when helping her Grandmother on the very rare occasions when her parents have taken a few much-needed hours for themselves.'
Gesturing to the Duchess, watching him from her seat around a table, he said he was 'especially grateful to be able to share the scope and magnitude of this work with my wife who joins me here this evening'.
Later, Prince Harry made a 'pinky promise' to an inspirational girl as she handed Meghan a bunch of white roses.
The Duchess of Sussex pulled out a white rose from a posy given to her Matilda Booth, 7, and told her keep it in her ‘memory box’.
Matilda, who suffers from spina bifida and is paralysed from the chest downwards, was also asked by Prince Harry to ‘pinky promise’ him that she would ‘never stop smiling’.
‘Never hide that brilliant smile away,’ he said.
Matilda’s mother, Sharon, told MailOnline: ‘They were just so lovely. It was very exciting. Matilda had watched the royal wedding and was very nervous about meeting them but they completely put us at ease.
‘They got down to Matilda’s level and she gave Meghan a posy. But she took one out and handed it back to Matilda and told her to keep it in her memory box. She made her feel so special.
‘Prince Harry also made her give him a pinky promise and told her to never stop smiling. He told her she had such a lovely smile. They also wanted to meet Simon, her toy dog. She is inseparable from him.’
The WellChild Awards celebrate the inspiring qualities of some of Britain's most seriously ill young people and the dedication of those who go the extra mile to keep children healthy and happy, including the outstanding health, social care and education professionals.