No one in the car was hurt, but all were shaken, she said.
"I had really upset children."
While the Nicholl family were regrouping on the opposite side of the road, a second car approached the same corner at speed, crossed the centre line and hit a power pole before bouncing back on to the centre of the road.
Mr Nicholl said he initially feared the driver was dead. "He was in a stunned state and I just made sure he was okay."
As Mr Nicholl was waving at traffic to slow motorists down, a third car "slammed" into the car in the middle of the road.
"Within that couple of minutes it could have all turned to carnage," he said, referring to the driver of a fourth car who managed to regain control of his vehicle on the same corner after it had "snaked" from side to side.
"There could have been casualties all over the place; the fact there was no casualties is a miracle really."
Emergency services from Milton attended before giving the drivers and passengers a lift back to the Milton police station.
It is not the first time this year Mr Nicholl has had a lucky escape. In February he was riding his bicycle on State Highway 1 when he was rear-ended by a car travelling at nearly 100km/h.
He suffered a broken collar, concussion, multiple cuts and abrasions.