The West Auckland couple moved to the Gold Coast about 10 years ago.
Mrs Bell, 27, was out with their 6-month-old daughter Emily and eldest son Nathan, 8, at the time of the fire. When she returned to the home she found Mr Bell outside with Kaiden, who was not hurt.
Mr Bell was taken to Brisbane Hospital and has already had one operation. Mrs Maclean said he faced at least a six-week hospital stay.
Mrs Bell, still too shaken to speak to the Herald yesterday, is staying near the hospital with their children.
Investigators are yet to determine the cause of the fire. The Bells had moved into the rental property only six weeks ago.
"They've lost everything, they just had what they were wearing," said Mrs Maclean. "Kayla's mum Annie ... there was a self-contained unit downstairs and she was living there as well. So they have all lost everything.
"The homeowners had insurance on the house, but because [the Bells] only moved in not long ago they hadn't organised their contents insurance yet," Mrs Maclean said.
Mr Bell had recently set up his own scaffolding business, and that would also be affected by his recovery.
Mrs Maclean has set up a Givealittle.co.nz page so friends and family back in New Zealand can help the family back on their feet. While that would be a long struggle, she said, the fire could have taken a worse toll. "They may have lost everything, but they still have each other."
How to help: visit givealittle.co.nz/cause/AdamandKayla