hi I read through your querry and understood your concerns. This is a quite common problem among the elderly. Many a times this symptom is just accepted with ageing. But it often treatable and has a few unnderlying causes that are more often overlooked. -If I were your doctor I would concider -cervical spondylosis, which is a condition causing degeneration of the spine that may result in compression of the blood vessels that are going to the brain and cause dizziness and double vision when sitting up. -Another important condition to be concidered is any ear pathology, the nerve that is going to the ear is responsible for hearing and balance of our body.This condition can be diagnosed by a simple audimetry. And is treatable. any minimal hearing loss or inner ear pathology can cause a sense of imbalance and cause her to walk in a uncordinated manner. These diagnosis have been considered as the other major pathologies like stroke have been ruled out. Wish u a speedy recovery ...!! god bless..