I am the "Agent" for my step-mother. In other words, she has given me her Power of Attorney. This document was prepared by an attorney and conforms to our state law. It specifically includes "banking powers", which evidently must be specifically added to be valid, at least in Florida. There is also a separate MEDICAL Power of Attorney, which is required to give me access to medical records, make medical decisions, etc etc.

Of course, a Power of Attorney self-destructs upon the death of of the grantor. Requirements may vary by state, but in Florida this document does not need to be recorded, but must have two witnesses. It should be prepared by a local attorney, rather than over the Internet or by filling in the blanks on a legal form that can be purchased at Staples or Office Max.

There are many cases of abuse by the Agent, and I don't know of any foolproof solution.