Waihape then allegedly fled the scene, and took the constable on a 2km pursuit that reached speeds of 65km/h, he said.
After later stopping, she was allegedly involved in a "struggle" during her arrest.
With Waihape in custody and in the back of a patrol car, police impounded the Subaru, but as they began searching the vehicle they discovered three more children, aged 4, 5 and 10, under a cargo cover in the car's boot.
Mr O'Sullivan said he was "shocked" to find so many children unrestrained in a car, during a scenario he had never witnessed before.
He said Waihape was the mother of six of the seven children, and a grandmother of one.
She was charged with driving while disqualified, failing to remain at a checkpoint, failing to stop and resisting arrest, Mr O'Sullivan told Hawke's Bay Today yesterday.
Waihape, who had been travelling from Gisborne to Napier, was due to appear in Wairoa District Court yesterday morning to face the charges but she failed to show and a warrant for her arrest was issued.
It's understood she would also be served with infringement notices for allegedly carrying the seven children in the car in unrestrained and unapproved car seats.
The RoadSafe operation discovered 12 restraint offences in Wairoa in about one hour.