I am psychically weak. I would not be able to lift the car off my own baby. I would be too conscious of my ability to fail. "Other women do it all the time," I'd be thinking. "Just lift." And all the while, my baby crushed under the chassis wheel, or wherever the baby lands under the car.
What happens if you lift the car and the baby's dead anyway from having a car on it? Wouldn't the shock just cause you to drop the car again, and splat! The baby would be paste.