All taking place in Calif.
Family Law Attorney
She had power of attorney prior over who? And, I think what you are saying is that she did whatever she did prior to death of that person, since powers of attorney expire at death, and the estate documents, if any, dictate what happens after that.
Assuming you have a copy of the will, you might want to contact an estate attorney in the county where the person died, and discuss the situation and the will with them.
The above is not intended to be legal advice, but may be used for general information. Please contact an attorney for specific help tailored to your needs.