My son and I live with my mother. She has dementia, but is in good health. She is difficult to deal with and will not listen to advice. I have a durable power of attorney, but she still controls her bank account. The problem is that she is spending money wildly and will not let me help her pay her bills, and is very secretive about her money. She has thousands of dollars in a checking account, which is not good. What is the best way to handle this situation?