Destiny-Rae is simply a record breaker.

Her kidneys stopped working properly when she was 10 months, making her one of the youngest ever to go on dialysis at Great Ormond Street Hospital, in London, and she's had to visit there three times a week for five-hour treatment sessions - adding up to nearly six months of her life rigged up to the machine, which a hospital record as the longest time yet for someone so young. 

Despite being on the transplant waiting list for years, the odds were stacked against her getting a new kidney, especially with people from her background being more likely to be a good blood and tissue match. None of her family can donate and there is a national shortage of organs, particularly from donors from an Ethnic background.

Her mum, Maria, had to desperately sought friendship and support in a chat room. And, by sharing her story, she met Liffy, who was willing to donate a kidney to a special organ-swap scheme.

Liffy is not a match for the 5-year-old, but her generosity resulted in Destiny receiving a kidney from another kind stranger who is. Maria, Destiny and Liffy were filmed as they found out if the UK Living Kidney Sharing Scheme, run by NHS Blood and Transplant (NHSBT), had managed to match them up with someone else - perhaps another parent who cannot donate a kidney to their own child who needs one.

This was their third attempt! "You can never force someone to willingly give you a kidney, because it's literally an operation they don't need,” Maria said.

“It's not an easy choice." But, without a transplant, Destiny's future would be uncertain, other than lots more dialysis.

"It's sad because that's her life," Maria says."Whereas other kids, maybe they get to go to do ballet or gymnastics... she doesn't.

"But she's strong, fierce and very intelligent. She's my inspiration."

When Liffy heard about Destiny, she immediately wanted to help. "What really stuck out to me was that Destiny was actually the same age as my own daughter," she says.

"And I couldn't imagine being in the same situation as Maria and Destiny and someone not wanting to help." A healthy donor, like Liffy, can lead a normal life on one remaining kidney - but it is a massive decision.

"You know, it would mean the most to be being able to see Destiny grow up a healthier, happier little girl. That's enough for me."

Of Liffy, Maria says: "She's literally sent from heaven – a guardian angel."

The UK Living Kidney Sharing Scheme uses algorithms to match the 300 recipients registered at any one time. Four times a year, NHSBT carries out matching runs to find the best combinations of recipients and patients.

The scheme is anonymous and confidential - people do not know who their donor or recipient is. And swaps go ahead only if every pair - up to three in total - can be matched. No patient misses out.

About a third of all kidney transplants in the UK are from living donors, which offers the best chance of success, as the kidney comes from a healthy person. The donor may stay in hospital for up to four days, with up to three months off work to recuperate.

They may be paid for expenses and loss of earnings but not for the kidney - it is a gift.

Following a successful operation, Destiny has started swimming lessons and is looking to go to Disneyland - the first real holiday she will have had, because the dialysis routine has been so restrictive. Liffy, who may never meet the person who received her kidney, said: "It would be lovely to see the face and see the person you have helped - but that aside, I know I'm going to see the face and see the person that I helped, because I see Destiny all the time.

"She calls me Auntie Liffy and I love it. I've met all of Maria and Destiny's family and they've met mine - with my two children adoring Destiny.

"And we are all extremely happy with it." About 60,400 people in the UK today are alive thanks to an organ transplant.