What a good grandchild you are. Unfortunately, her doctors are correct. Stroke kills alot of the brain cells and our brain is responsible for all that we do in life. Your grandmother is paralyzed on one side because it's likely that part of the brain that controlled that side of movement is gone. I'm sorry...
Hi there. Your grandmother suffered a hemiplegic stroke and has weakness of one-half of the body due to clot/thrombosis/hemorrhage in the contra lateral hemisphere of the brain. The doctors are right; the return to normal function is not feasible. You could consult a chiropractor for the extent of exercises and massage therapy possible. There are certain new theories linked, motor re learning, constraint induced movement therapy, brain repair with stem cells and electrical stimulation etc. based on assessment by medical professional, exercise should be the mainstay of therapy, taught by physiotherapist or medical personnel trained in neurological rehabilitation. Take care.