According to the dictionary
fidget (with something) to keep moving your body, your hands or your feet because you are nervous, bored, excited, etc.
Sit still and stop fidgeting!
My child keeps moving his head and the ENT doctor can not check his ear, but his body, hands and feet are still.
Does "stop fidgeting!" or "stop fidgeting with your head!" include to stop moving your head as well?