"It's just a shame for her.''
The mother, known to Ms Lee and her family only as `Sam', moved into a Housing New Zealand home last year.
She said she often saw the pair around the neighbourhood and the boy always looked happy with his mum.
"They would go for walks, they were just together all the time. That's why we feel so sad for her because she had a son yesterday, today she's got none.''
Ms Lee said the woman had since gone to Opotiki, where the boy's grandmother and grandfather lived.
Another neighbour said he ran outside when he heard screams.
He said the mother was clinging to the boy, who was covered in blood, and had to be told by paramedics to let him go so he could breathe, he told the New Zealand Herald.
Police continued their investigation today.
"We haven't got a clear understanding of what happened'', Mr Neutroski said.
He said police gleaned only a limited amount of information yesterday while attending the incident.
Constable Robyn Sadlier said she could not comment on whether the mother would face charges after the accident.
"We haven't made any decisions on that and we are not likely to for a while.''
Each year, five children died and one was taken to hospital every two weeks because of driveway accidents, SafeKids director Ann Weaver said.
One to three years olds were often the victims and were vulnerable because they are around the same height as car bumpers, she said.
Infants were more vulnerable because of their height.
