Police say the lady was in a white Nissan Pulsar on Phillip Island Highway, driving in the direction of Cowes when she misplaced management about 11.30am.
She clipped a automotive towing a caravan after which collided head-on with a Jeep.
The 63-year-old from Wonthaggi, south of Melbourne, died on the scene.
The nine-year-old boy within the automotive was airlifted to hospital with non-life-threatening accidents.
A person and girl within the automotive towing the caravan, weren't injured.
The person driving the Jeep was taken to hospital with minor accidents.
Police are investigating the precise circumstances across the collision and investigations are ongoing.