2013 Chevrolet Traverse drivetrain & axles problems

Wife went to park car in driveway between garage & street and when exiting the car, the car began to roll backwards. She tried to get back into car as 2 grand kids were in the back seat. After several attempts to get in, the car door knocked her down & the car continued to roll into street up on neighbors front lawn across the street. She was knocked unconscious and suffered bruises up & down her right side when I retrieved the car, found it in "park" & engine was turned off.

This has now occurred twice within the past 30 days. While in motion, the vehicle transmissions jerks, and speed is immediately reduced to 5MPH. The stability control light comes on as does the check engine light. A remote diagnostics scan from on-star identified 3 error codes: c0561, p0700, p182e. The first time it occurred while exiting a highway off-ramp. This vehicle was taken to the dealership.