Ten-year-old Rosie is one of six children whose designs have been featured on Big Mac boxes as part of McHappy Day celebrations.

People across Australia will be able to read about Rosie, who was diagnosed with Acute Lymphoblastic Leukaemia in April, by scanning a QR code on her design.

Mr Carroll said the project had been a pleasant surprise for the Wangaratta family.

“Rosie and I have been living at Ronald McDonald House since April and the opportunity came up for the kids to do some drawings,” he said.

“They were asked to draw what makes them feel happy; she drew us.

“Rosie’s drawing was selected – she’s quite ill at the moment and little things that make her feel special are pretty big.”

Rosie has undergone intensive chemotherapy and is living in an isolation room; the potentially catastrophic risk of secondary infection limits her ability to go out in public.

Due to the severity of the treatment, Rosie was required to stay in Melbourne, and Mr Carroll joined her while his partner Vanessa and Rosie’s little brother Zack stayed home.

Mr Carroll said it was not his daughter’s first experience with the Royal Children’s Hospital.

“She has moyamoya disease – that presented itself to us when she was three and had a stroke,” he said.

“She had surgery in 2010 to revascularise her brain; that won’t cure the disease, but it will let her live a reasonably normal life.

“Then in April she was diagnosed with leukaemia as well; they are completely unrelated.”

Despite what life has thrown at her, Rosie has stayed strong.

“To watch your child go through cancer treatment is extremely confronting … I’m just holding her hand – she’s the one going through it,” Mr Carroll said.

“She can still crack a smile when being given the most horrendous drugs.

“You try to be a strong advocate for your child and I draw a lot of strength from Rosie.”

Mr Carroll has also found support in the others going through the same thing.

“The resilience and the strength of children going through cancer treatment has to be seen to be believed – it has an innate ability to turn strangers into family,” he said.

“I don’t think people could possibly understand how much the Ronald McDonald House charities do for families.

“In so many ways it provides a bit of the normality to kids in the abnormal.”

If all goes to plan, Rosie will be home before Christmas, and will continue with chemotherapy until 2020.

Her story will be launched online this Saturday, on McHappy Day.