It was her cool head and quick thinking that saved the day, her mother Anna Crawford said: "Lucy identified the problem, advised me of the fire, got her sister out of the car and insisted I ring 111 straight away."
That combined with the fast response of the fire service saved the house from serious damage, Mrs Crawford said.
Thanks to the Firewise lessons Lucy had at school and kindergarten she was able to give her mum the correct advice.
"I said: 'No Mum, don't put water on the fire because it might be an electrical fire'," Lucy said.
Her persistence persuaded her mum to ring the fire brigade rather than get a bucket of water or try to find the fire extinguisher.
"I'm so pleased that I did," Mrs Crawford said.
"The fire was quite big. It was all up the back wall and onto the floor of the lounge. The black smoke was halfway down the street. The car was written off. The bumper on the front of the car was melted off.
"Another five minutes and it would have been a totally different story."
Mrs Crawford was so grateful for her daughter's actions and the education provided by the Fire Service that she emailed them to thank them and tell them the story.
"I am quite proud of her because I look at it and think our situation could have been a lot worse," she said.
Greerton station officer Richard Moreland said Lucy did everything right: "She's reinforced our Firewise programme at schools. Everything that she told her mum to do is what the teachers teach. That's the biggest buzz that it's getting through."
The family have had to replace a few walls near the garage but the house was not badly damaged.
It is believed the fire may have been caused by the battery falling off its bracket and pulling the wires off.
