Muscle twitches or fasciculations could be benign, a result of stress, nutritional deficiencies like
calcium and
vitamin D, but need to be evaluated clinically with proper neurological examination to rule out possibility of any abnormalty of conduction of motor impulses along the motor neuron from the brain. An Electro Myo Gram, EMG may be helpful. Get her examined by a Neurologist to rule out conditions like Motor Neuron Disease MND, or Amyotrophic Lateral Sclerosis ALS.