Zoe Palmer, 12, is facing a long recovery after contracting a severe case of influenza A, which progressed and attacked her brain and spinal cord.
A GoFundMe, titled "Zoe's Battle", has been set up to help the year 7 student with her recovery - which could take years.
Mum Sarah McBride, of Wangi Wangi, said Zoe's ordeal was "like a nightmare".
"You couldn't imagine it if you tried," Ms McBride said.
"It was so serious they said it was touch and go. We had no idea if she would wake up.
"She was a happy and healthy 12-year-old girl, who was socialising with friends in the holidays."
Ms McBride said the Belmont and John Hunter hospital doctors and nurses had "done an incredible job helping her stay with us".
"Every day she defies the odds. Every day there is a small win and a tiny smile, but a lot of tears in between."
Zoe's harrowing experience began when she had a sore throat on the Wednesday after the April school holidays.
"She had a fever and a cough and, by Friday, we were at Belmont's emergency department," Ms McBride said.
"She couldn't stop shaking. She had mottled purple arms at 7pm on the Friday.
"We only just made it to Belmont before she crashed. I had to prop her up and carry her from the front doors to the waiting area."
Zoe spoke to the doctor about her symptoms.
"About 20 minutes later, she was non-verbal and non-responsive," Ms McBride said.
Her case of influenza progressed to acute disseminated encephalomyelitis, acute hemorrhagic encephalomyelitis and acute necrotising encephalopathy.
"It's so rare. They haven't had a case like that here in Newcastle that we're aware of," Ms McBride said.
"There's been cases at Westmead over the years. Her neurologist said he hadn't treated the three things concurrently before."
She was in the paediatric intensive care unit at John Hunter Children's Hospital for 12 days.
"She was sedated and unconscious for a week, while the inflammation was being resolved with medication," Ms McBride said.
She's now in a ward at the children's hospital. Doctors estimate she'll spend eight to 12 weeks there before she can go home.
"We are really hoping to have her out of hospital before her 13th birthday in August," Ms McBride said.
Once home, Zoe will face a long rehabilitation process.
She's already doing rehab in hospital, working on her core strength, arm control, standing and sitting.
"She's awake now. We're watching lots of Disney. She's eating soft mashed foods," Ms McBride said.
"Drinking is more of an issue because sucking is not great. We have to tip water in very small amounts.
"She's still tube-fed through the night. She can only speak minimal words. She can't sit or stand on her own."
She is receiving full support from nurses.
"Her dad Ben and I are here every day with her. Sick leave is running out, so we'll do alternate days at the hospital and go back to work part-time."
Ms McBride said she had "spent three nights at home since May 3".
Her other daughter, 24-year-old Felicity, had been "looking after the house and cats, cooking and cleaning".
"It's been a big change for her too, to not have me there every day."
She said the family normally gets annual flu shots, but were delayed this year as Ms McBride was sick with RSV.
She urged people to get a flu shot and stay home when sick, so they don't spread bugs.
"There's so much going around. It seems like more than pre-COVID," she said.
She said ANE International had been a big help, as it raises awareness of acute necrotising encephalopathy.
