Mackenzie, 9, complained of being dizzy and tired. What came next was a parent’s worst nightmare.

Mackenzie Isedale was just nine years old when she was diagnosed with Acute Lymphoblastic Leukemia – a type of blood and bone marrow cancer, which affects the white blood cells.

And up until the day she was rushed to hospital, her mum, Errin Isedale, says she displayed no real symptoms of the potentially fatal illness.

“She’d had a little bit of bruising on her legs and she was tired and feeling dizziness, but there was nothing that you would think was sinister,” Errin, 40, tells Mamamia exclusively.

She says it was the first day of the Easter school holidays in 2016 when they noticed something was wrong.

"She got up on the first day of the school holidays and complained that she was dizzy, and my other daughter said she had white lips," recalls Errin.

From there, it was all a bit of a whirlwind.

"We took her straight to the doctors and they sent her straight to the hospital for blood tests, and at 3:30 the same afternoon, I got a phone call saying she had to go to our local hospital for chest X-rays, which would determine whether she could go in the car with us to the children's hospital at Randwick or whether she needed a helicopter ride," continues Errin.

It was something the family never saw coming, and they were understandably left devastated by the news Mackenzie had cancer.

"I didn't want to believe it. I was just blown away and shocked, and I just really didn't want to believe that that's what it was," says Errin.

"As a mum, I haven't thought of anything worse."

With the family based on the New South Wales South Coast and Mackenzie being treated in Sydney, Errin and her husband took turns staying with their youngest daughter, while trying hard not to disrupt their other daughter Jordan, 16.

She says they'd all go and visit collectively as a family on weekends though.

"[Not being there all the time] was really hard... I was like, 'Make sure you do this, make sure you do that.' I'd ask my husband what the doctor had said, and it just felt like he was missing out on some of the major information, which I know he wasn't," adds Errin.

Mackenzie's treatment and recovery was long and intense.

"She initially had nine months of intense chemotherapy, and then in January 2017, she started what's known as the maintenance phase, and that's chemotherapy tablets, which she actually finished last week," says Errin.

"Mackenzie was amazing. She ended up in a wheelchair for three months and she lost her hair. It was absolutely terrible on her, but she was known as 'Captain Smiley' around the hospital. She was a social butterfly at the hospital. She's very inspirational."

The trauma it caused Mackenzie and her family means Errin has only just started to feel like she can talk about it.

"I just wanted to take it all away," she says of her daughter's illness.

"You've got no control, and that's what hurt."

While wanting to protect their daughter though, Errin says she and her husband never hid anything from Mackenzie.

"I don't think she understood entirely, but we didn't leave her out of any information. It was happening to her, and we felt she was old enough to know what was happening," she says.

Thankfully, Mackenzie has now recovered from her illness, and is back to her old self.

"She's amazing. She just came back from a five-day Camp Quality camp, and she's playing soccer. She played touch football at the end of last year, and she's back at school full-time. You wouldn't know what she's been through," says Errin.

"She's very, very resilient. Lots of kids are. If only adults could take a leaf out of their book."

And Errin has some advice for other parents who may be struggling with similar situations.

"The road gets easier. It's a long, tough journey, but you've just got to kick cancer to the curb," she says.

"I think that's the biggest key: positivity."

Mackenzie is an ambassador for the Children's Cancer Institute's "Endure for a Cure" campaign, being held on Friday, May 4 - a 12-hour cycling challenge aiming to raise $400,000. All funds raised will go towards helping children like Mackenzie. www.endureforacure.org.au