A mother-of-four will spend Mother's Day at her son's hospital bedside, after he received stem cells donated by his big brother.
Four-year-old Ollie Cripps, who was diagnosed with acute myeloid leukaemia in June last year, relapsed in November a month after finishing his chemotherapy treatment.
When doctors told the family he would need to have a bone marrow transplant, his six-year-old brother Finley stepped forward and was found to be a perfect match.
Ollie underwent a transfusion to receive his sibling's stem cells at The Royal Marsden's Oak Centre for Children and Young People in Sutton, south London, on Friday.
Parents Fiona Cripps, 26, and Lee, 28, who also have identical one-year-old twin daughters, said Finley has been unfazed by the fact he could have saved his brother's life.
Ms Cripps, from Sittingbourne, Kent, said: "He was more excited about getting a week off school."
There was just a one-in-four chance that one of Ollie's siblings would be a match, but all three were found to be.
As the eldest and because he was the same sex, Finley was chosen for the procedure.
Mr Cripps said: "He wasn't bothered. I don't think he understands the severity of what he's done.
"He's never once turned around and said to us, 'I don't want to do that, I don't want to have an operation'."
Finley, who shaved his head in solidarity with his brother and to raise money for the hospital, admitted it was "scary" to go under anaesthetic on Thursday as he donated the stem cells.
But he cheekily replied "what operation?" when asked how the procedure - which involved taking bone marrow from his hip bone - had gone.
He was well enough to go home on Friday evening.
Ollie also appears unaware of the severity of his illness.
"He knows he's not very well on the inside but that's it," Mr Cripps said.
"Finley knows Ollie's got cancer but he doesn't understand what it is."
After Ollie's transfusion he was moved into an isolation unit at the children's centre, which is funded by The Royal Marsden Cancer Charity.
But with a weakened immune system, he could spend up to three weeks apart from his brother.
"They are used to it now, which is horrible, but they are," Ms Cripps said.
"Do you know what I find sad?," Mr Cripps added.
"The other week I went to the toilet with Ollie - he was picking his tubes up. He was caught, but he untangled himself.
"And I looked at him and I thought, it's sad. It's sad that a little boy like that knows to untangle his wires that are coming out of his body. But he's adapted."
Ms Cripps will spend Mother's Day in hospital by Ollie's bedside.
"For me, the perfect Mother's Day present has been a perfect stem cell match - I'm so proud of my boys," she said.
It is hoped Ollie will be able to return home in around eight weeks.
"It's going to be weird. This is normality, this is like a second home now," Ms Cripps said.
The family have raised more than £3,000 which has been donated to The Royal Marsden Cancer Charity-funded play specialists, who provide therapeutic activities to support children before they have procedures.