Casey Burke needs 25,648 people to make that donation, to be precise.

She and her pal, Matilda Duncan, five, have lots in common. They are both twins, and Casey’s sister, Carmel, is good friends with Matilda’s brother, Matthew.

They are all pupils at Coteford Infant School in Fore Street, Eastcote. Both girls also have cerebral palsy and cannot walk without assistance.

There is an operation that could help them walk unaided and, although Casey is not eligible for medical reasons, Matilda is one of a rare few who can have the life-changing surgery.

There is one major stumbling block – the operation costs a lot of money.

Casey wrote to the Uxbridge Gazette at Christmas with a special request. She said Matilda can have the operation at Great Ormond Street Hospital but the NHS is unable to cover the full cost, so Matilda’s family needs to raise just over £25,000. Could we help?

In her letter she wrote: “Matilda is only five and so doesn’t have enough money in her piggy bank.

“So, me and my mummy are helping Matilda and her mummy to raise the money.

“We need to ask 25,648 people for £1 each, but I don’t know that many people – so I need someone to help me that does.”

Mum Suzanne Burke said: “We know it’s hard to ask people to give money at this time of year but, if as many people as possible can give just £1, we might just raise the funds.

“I’m just a mum. I have no previous knowledge of fundraising but we just want to spread the word to as many people as possible.”

Mrs Burke said Matilda’s mum, Rachel Knowles, was ‘over the moon’ that Matilda was suitable for surgery.

“Rachel couldn’t believe it, because there is a long list of medical tests you have to pass,” Mrs Burke added.

“But she got a letter from Great Ormond Street saying ‘we’re very sorry but the NHS have refused funding’.

“To be eligible for it and to not be able to afford it is incredibly frustrating. When it’s your child it is terrifying and very hard to ask people to raise money.

“So I just said ‘I will do it’.”

The procedure, selective dorsal rhizotomy (SDR), concentrates on the lower part of the spinal cord and involves cutting the nerves that cause the symptoms of cerebral palsy.

It used to only be available in the USA, for about £93,000, but the procedure was brought to Britain in 2011, and until last August was fully available on the NHS.

To donate, go to Eastcote coffee shop Gri Gri, in Field End Road, where you will find a collection box for donations.

There is also a JustGiving page, www.justgiving.com/walking-Matilda , to donate online, or you can text the code MPJS50 followed by £1, £2 or £10 to 70070.