The girl, who held a Victorian learners permit, was driving a Suzuki Swift east along Great Southern Highway about 8.45pm when the car left the road and hit a tree near Trews Road.
Two passengers who sustained serious injuries were taken to Royal Perth Hospital by the RAC Rescue Helicopter, while the others were taken by ambulance.
Sergeant Mark Gubanyi, officer in charge at York police station, said the driver of the vehicle had been assisting police with their inquiries.
‘I cannot stress enough, we need to take care on our roads,’ Sgt Gubanyi said.
‘My officers at York police have worked hard and it has been well over 15 months since we have had a fatal or serious road crash.
‘We will continue to strive at our goal of Towards Zero.’
A spokesperson from police media said inquiries into the crash were continuing.
The cause is unknown but drugs or alcohol had been ruled out as a factor.
Anyone who saw the crash or the car before the incident is asked to call Crime Stoppers on 1800 333 000.