My husbands sister has POA for their father. She did this behind his back without consulting him. The father lives in Alabama and he had a stroke. A family member whom live in Alabama called my husband in Boston and said come down and check on your dad he just had a stroke. My husband called the sister to go check on their father because she was already visiting their mom whom has now passed in South Carolina. So my husband figured that she was closes to go see him. So the sister went to the hospital and the doctor said he was going to be fine but he do need additional assistant. So two weeks later the sister took it upon herself and removed the dad from the house and brought him to her home in north carolina. My husband was unaware of what she had done along with other family members whom live in Alabama. My husband kept in touch with her regarding the fathers health by cell phone,he called everyday and assured her that he was coming to Alabama to help out but he just started a new job and he has a family of six. Not one time did she say he was in North Carolina. So to make a long story short me and my husband just recently visited him in North Carolina at the sisters house. They argued the whole time and my husband want his dad back in Alabama were their is several family members willing to take care of him and all the services he need is in Alabama,the fathers sister lives next door to him and she is also hurt what the daughter did. So my husband started snooping around paper work and he found POA papers. A new life insurance policy was written and the sister was going out shopping buying massive amount of things. The sister already planned funeral arraignments and she is planning on placing him in a nursing home. The whole time we were their she said to my husband you are not taking him back to Alabama. My husband said yes I am he want to be in his own house and around the family. When the father arrived with her dad in North Carolina her kids told us that he was walking fine, now he scoots across the room and is left alone in the house. She feed him breakfast and then she is gone for the day shopping. When she go to work for twelve hours the visiting nurse is their for four hours and then he is on his own. She has really steep stairs in her home and my husband is afraid that he will fall. She will not allow my husband to read any medical records or take care of him for what reason we don't know. So she kicked us out of her home in a rage of him asking to Many questions. So now my husband do not know what to do to stop all this madness.
Your FIL gave POA to his daughter. No one has a "right" to have their parent ' s POA. If you believe she is spending HIS money on herself, then call APS; but try to have some evidence of wrongdoing. It really sounds like you are making a lot of assumptions.
When a parent has a stroke, someone has to show up and be the adult in the room. Your sister in law did that. Give her some credit.