"Ghost pressing" means that when you sleep, you suddenly feel unconscious, but your body cannot move. Actually, you have a sleep disorder. The phenomenon of "ghost crushing the body" belongs to a symptom of sleep paralysis in sleep neurology. During sleep, the patient is half awake and half asleep, and the brain waves are awake. Some people will also have hallucinations, but the muscle tension of the whole body is minimized.
In fact, the main reason is that your mother may be too tired some time ago, which leads to physical fatigue. As long as she has a normal rest, she will be fine. This kind of thing is very common and there is not much problem.