She rushed into the back room, grabbed the girl and her two-year-old sibling, and took them outside.
The woman, who didn't want to be named, then went back in and tried to push the burning mattress out the window to stop the fire spreading, but it was too late.
The children were unhurt but had been taken to Broadway Health for a precautionary check-up.
All the family's possessions were destroyed.
She said she was grateful to the fire brigade and to her neighbours, who had taken her children in and brought them food.
Two crews from the Kaikohe Fire Brigade attended, with fire chief Bill Hutchinson saying it was a reminder to store matches and lighters up high, where children couldn't reach them, or lock them away.
"It could have ended in tragedy," he said.
Fire safety officer Roy Brickell said it also reinforced the need for smoke alarms, because they provided early warning and gave people more time to get out - vital in a fire like yesterday's, which spread within minutes.
He also urged people not to go back into a burning house.
"Our message is, get out, stay out."
The home was owned by sisters Rebecca and Rachael MacCarthy, who used to live there but now rent it out. It was insured.
"I'm just glad everyone's okay," Rebecca MacCarthy said.
The family will stay with whanau in Kaikohe until new accommodation can be arranged.
The woman saved her father's ute, which was parked in the carport, by pushing it out of reach of the fire.
