An 8-year-old called for help when the car their mother was driving crashed down a bank on Great Barrier Island.
Police said they received a report of a person trapped in a vehicle on Aotea Rd, above Palmers Beach on Great Barrier Island about 8.38pm last night.
Three people had been in the vehicle when it rolled at low speed over a low bank.
The chief intensive care paramedic for the Auckland Rescue Helicopter Trust said the 33-year-old woman was flown from Claris Airfield to Auckland Hospital in a serious but stable condition.
Police are investigating the circumstances surrounding the incident.