1. those with too much fluid in their system 2. those with contraction of the arterioles forcing the pressure to rise 3. those with a high heart rate forces pressure to increase. Someone can also have a combination of these problems as well.
So without additional info I cannot say if diet, lifestyle changes, or medication is what she needs. I can tell you this: you must take care of it as high blood pressure slowly destroys all end organs (brain, liver, kidneys, heart, lungs).