If she feels pulsating and a steady pain with a deep quality as if it is boring into her, felt most prominently in the middle of the abdomen and sometimes radiating to the back, she must visit her physician as soon as possible.
This can be an abdominal aortic aneurysm (a localized widening of the aorta, one of the large arteries through which blood passes from the heart to the rest of the body).

Best wishes!
Marija