Recounting the day of the crash, she said the Kamo Primary School pupil from Whangārei was visiting his grandmother and father in Wellsford when he was hit in the 50km/h zone about 5.30pm.
"His dad found him. He pretty much heard it. He went running on the road and he saw our son on the ground. He was pretty much in the gutter.
"His dad had to resuscitate him. He said 'Dad' and then he lost consciousness."
Fiazco, who has an older brother Odeon, 14, spent up to 10 days in a coma but is now awake.
However, Lewis said her son couldn't talk or walk despite being moved to a ward.
"Now he's got major brain injuries. He's going to be suffering from his injuries for the rest of his life. We pretty much have to teach him how to do everything again."
Lewis said her son also suffered a fractured rib and collapsed lung and had "tyre marks" on his leg.
She said the driver stopped. Police were tonight unable to say if charges had been laid.
The 29-year-old mum had just bought a car when the accident happened and collected it the day after her son was rushed to hospital.
While she stayed at Ronald McDonald House on the hospital campus the car, a silver Mazda Atenza, was broken into and stolen.
Also inside the car were some of the gifts sent to Fiazco from family and friends.
Lewis said the $3000 car was uninsured because she had been so busy caring for her son she had not had time to fill out the paperwork.
"It's just absolutely low that somebody would steal my car. It was stolen from right outside. We really need this car."
She had been forced to walk everywhere and said when Fiazco is finally discharged she doesn't know how the pair will get home to Whāngārei.
A Givealittle page has been set up to support the family.