Do you think that its right robing your father in law? What should my family do?

My Uncle died 2 years ago, and my aunt is now taking care of my grandfather. When I was in 3rd grade my aunt and uncle bought the house that was my grandfathers for a extremely low price because of the verbal Promise of taking care of my Grandfather for the rest of his life. Any way my aunt got fired from here job because she wanted to take his sons on a trip. Recently I saw a letter from my Aunt addresses to my Dad demanding he and his brothers pay 70$ a month, also in the letter she states that she has emptied ya emptied my Grandfathers bankacount and needed more money. She has not looked for a job, the truth is that she want to be payed for taking care of my grandfather. I did the math and since she cashes his SS Checks she gets 240 a month and onto of the 70 $ *4 that is way over 6K. I told my Dad that he should consult a lawyer but he doesn't want to get my Grandfather upset. Do you think that its right robing your father in law? What should my family do? Thank you for your help