Mom has dementia and my sister is using mom's checking and debit cards to pay for her stuff. She has made mom over drafted for more than 5 months and has never paid it back. What can I do about this?

Call an elder law attorney asap!! And find out if anyone has POA. If no one dose she is steeling from her sister! I care for my husbands grandmother and one of her granddaughter was doing the same thing. Even went to far as to take her to a lawyer to make a new will! This same granddaughter stole money from her bank account and almost left grandma with nothing! We also contacted the DA and they had us send them all the paperwork and doctors letters stating for over 4 years she has been incompetent because of the Alzheimer's. They are now going after her for elder abuse and also the lawyer who let this woman sign when she can't remember not two mins. after you tell her something! Grandmas daughter has DPOA and I have medical since she lives with me. And this granddaughter just wants everything of grandmas and is not entitled to it. Its an ugly mess but grandma needs protection and from the sounds of it so dose your mom! So get on the phone and call before your mom has nothing left to help in her care because she is going to need it!