"What the doctors don't know yet is if he'll be able to breathe on his own. They're waiting for him to stabilise so they can find out about his breathing," Mrs Steedman said.
Cooper and Geordie had moved to Whanganui to be with their mum, Kim Ostern, just four days before the accident, she said.
Mrs Steedman said she set up the Givealittle page to help the family with travel to and from Christchurch, and other expenses.
People have made donations of between $5 and $1000. At least two individual donors have pledged $1000 each.
Many people wrote heartfelt messages to the Snowdon-Ostern family along with their donations.
Donna Harris donated $100 and said she understood what the family was going through.
"My husband is a quadriplegic of three years at the age of 41, due to a mountain bike accident. Take one day at a time. Thinking of you."
An anonymous donor said her 16-year-old son had cut his hand at the park.
"Ten stitches later and it was put back together. I didn't cope very well at all so I can't even begin to imagine what you are all going through following such a massive accident."
A Christchurch resident named Donna was touched by the fact the family knows no-one in Christchurch, and left her phone number.
"I live close to Burwood Hospital and would be happy to help out in any way. Would really like Cooper's mum to call me."
Lisa said she became a paraplegic at the age of 16 and she was heart broken to read of Cooper's plight.
Donate to Cooper here.
