My grandfather and grandmother is being Harrased by my aunty

Hello, My uncle past away few days back and my uncle don't have any kids, few days later my aunty start Harrasing my grandmother and grandfather for money and property. She keep shouting on them and also torture my father to send all money they have. My father have already gave alot of money for care and she even lives in my grandmother home her all expense are on my grandmother and grandfather. But now she needs everything and she keep fighting for that. My grandfather is all 70 year where my grandmother is all 65 year both are suffering from high BP and my grandmother is suffering from Atherites where she is little in depression by all her behavior. She handed all money which she got from insurance companies to there brother. Not only she but also her brother keep Tourtuting us for more money. She keep fighting with us. My both grandmother and grandfather want to hand over whatever government will say but they don't want her to live in there House. What are the right of my grandparents and what can we do?