My RN sister is overwhelmed and nasty, I'm worried about my Dad. What do I do?

My dad is dying of stage four liver cancer and my sister insisted on taking care of him in her home. She is an RN who has not been in active nursing for a while, she works for an insurance company. She has never been compassionate and enjoys people thinking she is a saint. She was a golden child of our abusive parents, I was raised with no self-esteem and lived on my own since age 14. I am very sick now with the same problems as my dad, only lungs.

I visited my dad, who was planning on paying off the mortgage on my house, there is a little bit left, as the mortgage is in his name and no mortgage insurance. He tried to show me his will but it was missing, he wanted me to have a copy, he was very upset that he could not find it. I am the second executor. My sister got him to change this will and then started giving him pain meds and morphine and cut off contact with me. I asked for a copy of the will and it leaves everything to her and her kids. Even the repayment of his debts are up to her discretion, and I have been removed and her son replaced as backup executor. She has gotten rid of his personal possessions though I have a right to half of those, which is basically some clothing and some papers perhaps and photos. She screamed at me for asking for an inexpensive momento be sent to my eldest son, who bowed out of receiving anything from the estate and gave his share to my sisters granddaughter.

My sister always hit her kids, as did her husband, and my parents even saw her push her son with cerebral palsy down the stairs and then kick him on the ground. When the kids were teens they asked me why their mother didn't love them. I covered for her, for the kids sake. My sister also stole money from a house by harrassing our mom out of a lifetime lease she had. I tried to warn my dad not to make her his caregiver and representative.

My sister resents my dad was paying off my house. she flew into a rage because I emailed her, thanking her for helping my dad and explaining to her that I may have only a couple years left and I am so poor. She starting complaining about caring for him and sent me a nasty hand scribbled letter with all caps and underlines on words and a new will that was unsigned, undated, no attorney name and leaving everything to her and her family.

I asked if I could have the attorney's name who did the new will and she refused and screamed at me how she was cleaning up s*** and vomit and she can't deal.

My mom says the new will is suspicious and my dad would not have agreed to some of the changes if he knew. But he is too zonked now to talk. They claim he has "fallen" in the middle of the night several times.

My sister has told me that mom and dad "beat the s*" out of her, she has always felt entitled.

This whole situation feels very wrong and my sister needs help, mental help. She is on medication for a psychiatric condition. I think she may have had some trouble as a nurse. She's a narcissist with a significant narcissist fan club. Few really know her.

I live several states away from her, she is in Indiana. APS is part of criminal justice there. I would like someone to check on my dad in light of what I know and have documented. This is abuse, right? Just before this, my dad called and was so sad and said he missed me and that my sister told him that she was going to call me and have me come see him in October but she said he is out of his mind. I have not heard from him. My mom says he can no longer talk due to coughing and sleeping so much.