The woman was rushed to the intensive care unit from the Mundijong Road crash site on Tuesday.
Major crash continues their investigation into a serious crash in Mardella on Tuesday.
Authorities said a woman veered her four-wheel-drive off Mundijong Road in Mardella around 12.40pm on Tuesday.
It's believed the woman lost control of the vehicle, causing it to spin and then plough into a tree.
The driver received several injuries and was rushed to the Royal Perth Hospital intensive care unit where she remains in a critical condition.
Mundijong Road remained closed for several hours yesterday with emergency services working over three hours to clear debris and rush the victim to hospital.
Investigations continue.
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