Aunt by marriage, uncle passed, she was deemed unfit, her family now in charge, my family had taken care of her for several years

My uncle died about 5 years ago, my aunt who had suffered from a stroke previously, but was of sound mind got ill and was taken to hospital after a fall and deemed unable to make her own decisions. My mom (uncle's sister) and father had been taking care of her by bringing her groceries, taking her to doctor, managing the household chores, etc. until the fall and hospitalization. When she was deemed unable, immediately the hospital sought out her sister who has not been involved and she swooped in because my uncle had some money, land, etc. when he died and he always said that her family was about what money they had. Anyway, now the sister has cut my parents out of her life entirely, changed the locks to her house and property the first day, and move her into the sister's daughter in law's home which has several people living in the home. Now, my family has seen in the paper the real estate transactions selling off properties. My mother is the executor of my aunt's will (and my uncle's will which was not probated but he left everything to my aunt), and my aunt in her will named me as her heir, nothing for her family. Now, I am worried that her sister and her family are only after my aunt's money and once it is gone will dump her off at the Nursing home again. What can I do?