Six-year-old Mitchell Ray of Dubbo loves his baby brother Connor who was born four days after he was diagnosed with stage four cancer.
But their time together at The Children's Hospital at Westmead has been limited because of Mitchell's life-threatening condition and the six-week-old baby's struggle to breathe because of laryngomalacia.
Mum and Dubbo Hospital dietitian Erin, who had breast cancer surgery when pregnant with daughter Hannah, is currently looking after Connor at Ronald McDonald House near the hospital.
Dad Jeremy, a security officer at Dubbo City Regional Airport, hasn't left Mitchell's side since he was diagnosed with the rare neuroblastoma in mid-January and flown to the Sydney hospital's intensive care unit.
The family is desperate to stay together and to that end supporters have launched a fundraising campaign at www.gofundme.com/f/mitchell-blasts-neuroblastoma to help with mortgage payments and other bills.
The target is $20,000 with $8355 raised so far.
"We're so grateful for all the support to help us remain as a family here in Sydney rather than having that extra stress of not knowing what's happening with our children while being separated," Mrs Ray said.
Unresolved pain led to the discovery of a large tumour in Mitchell's abdomen and metastases in his lungs, lymph nodes and bones.
The Dubbo West Public School student faces up to 18 months of treatment including chemotherapy, a stem cell transplant, surgery, radiotherapy and immunotherapy.
"He has responded to the chemo he has received so far," Mrs Ray said.
"We keep at this and keep thinking the best until we hear otherwise."
Meanwhile, Connor is currently dependent on a CPAP machine when he "naps".
"We just need to keep using this machine to make sure he keeps breathing," his mother said.
Mrs Ray dares to imagine her children playing together in their "beautiful" and friendly neighbourhood in West Dubbo.
"It's all overwhelming and everything a bit uncertain," she said.
"But the support of our family and friends, that's really been a blessing and helped us get through.
"We will just wait and see and hopefully do our time here and then return back to the life we used to have."
The brave mum of three watches Mitchell when he is with Connor, both of them the image of their father.
"Oh he loves him," she said.
"He was so excited to be a big brother again. He's good at it too."