Sister's extraordinary sacrifice for critically ill sibling

Millie Trustrum's parentswere given the option to stop treatment for their daughter when the cancer that had invaded her body and previously been treated came back with a vengeance.

One doctor told them they could give up, take Millie home and try and "make her comfortable" until the inevitable happened. But they weren't ready to give up.

It all started when Millie, now 13, was in primary school in their hometown of Lismore, NSW and began complaining about pain in her shoulder.

"We thought it was just [that] she'd got on a trampoline," her father Kevin tells 9honey.

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One evening, the pain became unbearable and her heart was racing.

Kevin and his wife Erica decided to take their daughter to hospital in Lismore, where it was discovered that her left lung had filled with fluid.

While her lung was being drained, a tumour the "size of a grapefruit" was discovered just behind the little girl's heart, which was "putting pressure on everything".

At this stage they didn't yet know if it was cancer.

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Tests eventually confirmed Millie had T-Cell Lymphoblastic Lymphoma, a rare and aggressive type of cancer that primarily affects the lymphatic system.

The family were transferred to Queensland Children's Hospital and Millie underwent chemotherapy that night.

As they struggled to process what was happening to their daughter, the youngest of their three children, their community and family did what they could to support them.

"People started cooking food and wanting to do things for you," Kevin says of that time. The family were also supported by various charities.

At first the chemotherapy worked.

"It looked really great for the first couple of months," he says.

"The tumour was nearly gone at the end of three months."

Millie's overall health, however, was struggling and the decision was made to take a break from treatment.

"So they stopped treatment for a little period and in that time, her cancer came back really quickly," he recalls.

Millie's oncologist gave the family five options, four of which were new treatment options and one was to "just bring her home and make her comfortable".

Not ready to give up, Kevin and Erica went with their doctor's advice on which course of treatment Millie should try. Miraculously, it was effective against her disease.

Next, she would undergo a bone marrow transplant.

"The whole family got tested and we were very lucky that both Millie's sisters were compatible bone marrow donors," Kevin says.

Sister Olivia ultimately donated her bone marrow, as she shared the same blood type as her sister.

Today, the family is thankful for Millie's restored health and determined to give back.

"It gives you a different perspective on life, and I guess that's where we've gone down this route now of working out, as a family, trying to make the world a better place based on the experience we've had," Kevin says.

"That's Millie's mantra as well. Her passion is to raise awareness and raise funds for child cancer research so that no kids have to go through what she did."

This weekend, the family is taking part in a fundraiser for The Kids' Cancer Project called K'Day Day on February 15, which is International Childhood Cancer Day.

"K'Day is where we ask everyone to replace G'Day with K'Day," Kevin explains.

"And on that day we ask everyone to donate some money to childhood cancer research and The Kids' Cancer Project.

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As part of the fundraiser, the family will be at Coogee Beach in Sydney from 11am on February 15, where 2,000 K'Day hats will be handed out to passers by and skywriting that spells out the word "K'Day" will appear.

Every donation on the day will be doubled by the charity's business partners.

"Any donation that's made today or tomorrow will be matched by their business partner," Kevin said.

"So we get double the impact for childhood cancer."

Follow The Kids' Cancer Project on social to stay up to date.

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