Power of Attorney

My mother signed a POA appointing me as her Atty. in fact and my children as the Successor AIF's. In doing so, she removed my sister as the Successor (my sister was having substance abuse issues and was under a psychiatrist's care for depression (a 25 year bout with depression) and substance abuse). About 6 months after signing the new POA, mother was diagnosed with early dementia and early Alzheimer's. My sister is now demanding that she be re-instated as the Successor. She has absolutely no relationship with anyone in the family, including her own children, one of whom has signed an Order of Protection for Stalking against her. No one in the family has any problems with the way mother is being taken care of (except the one sister) and NO ONE in the family wants this sister (who, by the way lives 450 miles from mother) to have anything to do with making decisions for mother. My question is: Since mother has been diagnosed, can she change her POA at the point in time? My sister is relentlessly harassing my mother to get the POA back to the way it was prior to my sister's hospitalization and subsequent commitment for alcohol abuse.

Is there any kind of power of attorney under which if the principal's wishes conflict with those of the agent, the AGENT's decision will govern? If so, can that type of POA be ended by the principal or by a court?

Can I list both of my sons as agents on a POA, not one first then the second, but the two as one son or the other son?

In the proxy forms, I want to appoint a non-attorney to represent me at a meeting, but the language say 'do hereby constitute, appoint and name-as my true and lawful attorney and agent for me-. If the person is not an attorney, should I take that word out of the language and just keep the 'agent' part?

My father executed his Power of Attorney on 11 May 2005. It was prepared by a lawyer. My stepmother is named as his Attorney-in-Fact. I am his daughter and was named his alternate Attorney-in-Fact. His wife is incompetent to manage his affairs now due to Alzheimers. I have tried to place his POA on the record at his bank after numerous confusions and delay as to it's authenticity, i.e., date of instrument and authorized copy. The impressed 'seal' does not come through on the photocopy as authorized by the POA. The bank is stating that he needs a POA with a 'current' dated copy. His condition with Parkinsons is a debilitating disease and he was diagnosed in 2004 and then he executed his POA in 2005. What authority does the bank have to deny acceptance? The notary that notarized the document's commission expired in 2007. I have been a notary for 30 years and I would think that anything that I notarized years ago are still good documents on the records. Is the bank just giving me the run around and don't know how to handle this POA?. I live in Maryland and my father lives in New Jersey. His POA was done in NJ. This is my third act dealing with family members and I have had no problem acting for a loved one. Also, can I attach a Physician's Statement as an addendum to the POA?