She needs to have her medications looked at...

What does she take now? Some OTC drugs commonly used in the elderly like Pepcid and Zantac can cause this too.

Also I'd recommend a B12 test. Many older patients are low in this and doctors don't consider it or offer testing for it.

There is a simple test called the Romberg's test. This needs two people. One to stand behind the patient, not touching. The suspected low B12 patient closes the eyes, and if they fall back,
that is a sign of low B12 too... then blood testing should be done.
B12 serum level should be 400 or higher in US...don't accept "normal" from the doctor who will consider 250 "normal".
A serum MMA test can also be done with it and be revealing.

NIH and Dietitican groups recommend B12 supplements for all people over 50 now.

Another common cause of dizziness is wax buildup in the ear pressing on the ear drum or fluid build up from the middle ear on the other side, pressing out. Any pressure on the eardrum, creates dizziness.
I would caution not to put the head back at the hair dressers... doing that may compress the vertebral artery, and has been implicated in elderly stroke:

http://en.wikipedia.org/wiki/Vertebr..._insufficiency