Bone marrow donor matches are made by matching people of the same ethnic heritage, for Tania Murphy time is quickly running out to find hers.

Her family are hoping the power of social media might help link her to the donor she needs.

The mother of two with Croatian-British Isles-Australian heritage was diagnosed with leukaemia July 7, 2016, after weeks of feeling rundown.

Doctors were amazed she was able to stand after seeing how low her white blood cell count had fallen.

She was immediately admitted for a one-week, 24-hour chemotherapy treatment.

After two more rounds of chemotherapy and an unsuccessful worldwide search for a donor match, the 42-year-old now feels trapped.

"It's like being in a straightjacket — I'm helpless," Tania said.

Ethnicity the key to bone marrow matches

Unlike blood, bone marrow is matched by ethnic origins and not specific types.

Family members are usually tested first, then open-donor searches are carried out for people with similar origins.

Doctors told Tania she would require a marrow transplant following her second chemotherapy treatment.

Unable to find a match, her leukaemia flared once more and she was given a third round of chemo.

"If the cancer comes back, and I don't have a donor, it's basically death," she said.

Chris and Tania celebrate a fourth birthday with Tayla and Kalam. ( Supplied )

If love could cure leukaemia, Tania would not need a donor.

Her husband Chris rarely takes his eyes from her and the two remain positive, talking about how they will celebrate their 10th wedding anniversary on December 1, 2017.

It is a long way away, but the couple see it as their goal to get there.

The small community of Middleton, on the south coast of South Australia, has rallied around the family.

"We don't know what the future holds, but we will deal with what we have today and make it as great as possible," Chris said.

The couple know the cold facts: between 20 and 25 per cent of applicants will not find a perfect bone marrow donor match.

Chris though refuses to give up hope that the family will find a matching donor.

"We plan to get old together and see our children get old and there is no point in thinking what if [we can't find a donor]," he said.

As a family, with their two children Tayla and Kalam, they have faced each stage of the disease together.

Tania Murphy dons her Wonder Woman costume as she endured another round of chemo, with Chris never far from her side. ( Supplied. )

When the children visited Tania in the hospital during her chemotherapy sessions, she made sure the visits were not doom-and-gloom.

She would play cards, hide toys and make sure they knew their mother was OK.

When the second bout of chemo caused Tania's long, curly blonde locks to fall out in clumps, the children noticed something was not right.

"They didn't say anything for a while and then said 'Mum, can you take the scarf off?'," Tania said.

"I took [the scarf] off and my son Kalam said 'you're still beautiful Mum'."

The desperate search to find a match

As the need to find Tania a donor match escalates, friends of the family have set up a Facebook page.

The page quickly gained followers, with a hope to encourage people of all ethnicities, between the ages of 18 to 45, to have their blood tested for marrow donations.

Potential donors can also find more information through the stem cell, bone marrow and cord blood site Gift of Life and register their interest to donate at Red Cross Blood Banks.

With a six-week window from blood test to registration and Tania's window of opportunity quickly closing, Chris remains focussed on finding a matching donor.

"Challenges come up and you just have to face them and together we will work through this — it's all we can do," he said.