ROSIE Crundwell was your typical smiley and active three year old and so when she complained of a sore tummy, her parents thought it was just constipation.

But her world was shaken upside down after mum Jasmine spotted bloody urine in her nappy.

"We took her straight to the hospital," Mrs Crundwell said.

"They basically thought it was a UTI but things weren't matching up.

"Her extreme blood pressure - it was higher than an adult's.

"She got admitted, then got an ultrasound; then we saw the mass on her kidney.

"Obviously the sonographer didn't say anything but I could see the measurements.

"But never in my wildest dreams did I think it was cancer.

"It was just like a movie, they came in and said we need to have a serious conversation.

"It's like an out of body experience learning your child has cancer.

"That night, we were flown down to Brisbane with the Royal Flying Doctors (Service)."

Mrs Crundwell said they left with only a handbag, forced to leave her younger two-year-old daughter behind because of COVID restrictions.

"Fortunately my husband flew down the next day."

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Mrs Crundwell said her daughter would need surgery - likely to be over the Christmas period - to remove the Stage 3 Wilms' tumour which has entirely taken over her right kidney.

But first, Rosie must go through three types of chemotherapy to reduce the tumour's size and eradicate any broken-off pieces of the cancerous cells in her bloodstream.

Mrs Crundwell said blood tests and chemotherapy were administered via a portacath inserted under Rosie's skin connecting to the main vein next to her heart.

Meanwhile, the family must take particular care as Rosie's depleted white blood cell count makes her neutropenic.

"Now she's losing her hair from the chemo," Mrs Crundwell said.

"She does see it falling out but doesn't say very much.

"She knows we're trying to fix her tummy.

"She says, 'Mummy, I want to go to school. I want to go home'.

"Kids are so resilient, they just want to be better, they don't want to be sick.

"My heart is absolutely broken for her but Rosie's strength keeps me going.

"Anyone who knows Rosie, she just lights up the room; she's just the sweetest little thing.

"She makes anyone smile with her big blue eyes and belly laugh, even in the hospital."

Mrs Crundwell said the hardest part for her daughter was being separated from her little sister and best friend Felicity, who was being cared for back in Walkerston by her grandparents.

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The young family, who have been down in Brisbane since early November to be near the hospital, hope to be reunited over Christmas - if only for a few days.

For now, they anxiously wait for a confirmed surgery date, after which Rosie will require months of chemotherapy and radiation.

"Once that tumour is out, she probably will start feeling better," Mrs Crundwell said.

"Every day is so unknown.

"Her body changes all the time and copes in different ways."

Mrs Crundwell is now urging other parents to trust their instincts.

"When it comes to your child, you know when there's something not right," she said.

To follow Rosie's journey and donate to help the family, head to 'Rosie's Fight Against the Wilms'.

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