This guy raises some good points.
No, actually they weren't good points at all, and actually retarded. A low IQ mother stuck in a phase of shock, with a child scared for their life and having a massive adrenaline rush. There's nothing unplausible about that.
Have you ever been scared to the point you felt your life was in jeopardy? You tend to be physically able to do things you normally wouldn't expect of yourself.