My sister is a trustee, and she constantly says she is going to work on my mother's estate for the last 5 months. She says that my mother told her to not allow herself to be rushed by the other siblings, and she needs to honor my mother's wishes pertaining to privacy and time. She read a letter from the attorney informing the beneficiaries of the process two months ago. However, we have not received it as of yet. Also, we question her motives because we believe she might have used my mother's money when she was the power of attorney. How do I go about dealing with this matter?