A 12-year-old girl is seeking a compatible donor so she can receive a life-saving bone marrow transplant, but family and friends warn time is running out for her.

More than £80,000 has been raised for Libby Cotts, from Buckhurst Hill in Essex, who has severe aplastic anaemia, a very rare condition which means her bone marrow does not produce enough blood cells.

Her GoFundMe page is raising money for test kits to find a bone marrow donor. It has received thousands of donations and been shared by celebrities – but her condition has worsened in recent days.

Since her diagnosis in October, Libby has been receiving blood and platelet transfusions to keep her alive – and these are now becoming increasingly regular.

Lucy Tant, 38, one of half a dozen close family friends helping the campaign, told the PA news agency: “She doesn’t have much longer left… we’re on a knife-edge now.

“They haven’t given Gemma, Libby’s mum, a time-frame because she hasn’t pushed for it.

“But yesterday was the big wake-up call that we were all in denial… Libby got a very bad headache and was up all night with her gums bleeding, she’s got blood blisters in her mouth. She’s now back in hospital.”

Libby’s condition means she is prone to severe bruising and bleeding – she was diagnosed after being struck by a hockey ball last year – and her immune system is compromised.

On Tuesday evening, Libby’s family said doctors are concerned the repeated blood transfusions could cause damage to her heart and liver.

The only cure for aplastic anaemia is a transplant, but this requires finding a compatible donor.

A donor was previously found for Libby and on December 21 she was admitted to Great Ormond Street Hospital in preparation for a six-week treatment programme – but this fell through when she was told the donor was no longer compatible.

Ms Tant added: “Libby’s amazing, she is so inspirational to all of us – her strength, her character.

“It’s only been the last few days, really, that we’ve kind of seen Libby go downhill and her spirits go.

“As a person, Libby’s adventurous, she’s a little bit crazy, she loves swimming, horse riding, playing hockey at school… we don’t know when or if she can do these things again.”

Libby’s family and friends have created a GoFundMe page which aims to raise £500,000 for blood cancer charity Anthony Nolan, which is helping her to find a compatible donor.

Every £40 translates to one bone marrow testing kit and the family is also encouraging people, particularly those aged 30 and under, to register themselves to be tested.

Evidence shows younger donors are associated with better survival rates for patients.

Libby’s cause has been shared by a number of celebrities, with business mogul Lord Sugar, snooker player Ronnie O’Sullivan and Newcastle United footballer Andy Carroll amongst those issuing pleas on social media.

On Tuesday, a donation of £7,300 was pledged to the cause alongside the message: “From your loving friends from across the Pond!”

Ms Tant said: “We can’t believe the generosity of people… we are just so overwhelmed.

“It’s amazing what people have done to help us… it’s just so sad that we just need so much more.”

Ms Tant added that the pandemic has made Libby’s situation even more difficult, with Anthony Nolan facing a huge deficit in funding due to reduced donations and even disruption to the postal service causing issues with swab tests.

“If Covid wasn’t around this would have been so much easier and Libby wouldn’t be in this position… we would have had a donor by now,” she said.

If you would like to donate to Libby’s cause or register as a bone marrow donor, visit libbys.lockdown on Instagram or www.justgiving.com/fundraising/loveforlibby.