I appreciate and understand your concern for your granny. From your description, it seems she is going into a complication after stroke - vascular dementia which is giving rise to the hallucinations and behavioural symptoms. It is a progressive condition which can be prolonged but not cured. One may choose to control the symptoms using conventional medicines or homoeopathy. Both are equally effective.
Next Steps
you may approach a psychiatrist (Homoeopath / Allopath)
Health Tips
It is advisable for the family to get a detailed insight about the illness and supportive management. You may contact me via Practo portal for further info. Warm Regards...