Laura Roe, 25, had part of her liver removed and given to baby Cameron in a rare operation.
She decided to go ahead with the surgery when medics feared little Cameron, who is one, would die before a deceased donor could be found for him.
The family, from Manchester, say that Cameron is now recovered and thriving at home.
Laura's liver will regenerate to its normal size in her body, whilst the donated piece in Cameron will grow with him.
Laura had her operation at St James's Hospital in Leeds, after tests on Cameron's dad, Giles, 35, showed he was not compatible.
Whilst Laura had her surgery, Cameron was in theatre at Leeds General Infirmary waiting for the organ. It was rushed across the city by ambulance and transplanted into him with surgeons on a video link between the two theatres to ensure all went well.
Cameron was allowed to go home 15 days later.
Laura said:'We took him swimming for the first time this week and it was amazing.'
What a lovely story!