Thanks for your question-- I'm sorry your mom is going through this. Has she been diagnosed with anything connecting to the twitching? Twitching is many times connected to Multiple Sclerosis, a spinal injury, or Muscular Dystrophy. However, there is something known as Benign fasciculation syndrome or BFS which is twitching of various voluntary muscles in the body. The twitching can occur in any voluntary muscle group but is most common in the eyelids, arms, legs, and feet.
If your mom is starting to feel symptoms in other parts of her body, she should see her primary care physician or neurologist to help rule out any and all possible causes.
All the best to you and her,