My father is in frail health. He has named his granddaughter as Power of Attorney, but my mother, sister and I do not trust her. We believe she is abusing her position as POA. Neither do we trust my nephew who is also acting in a legal and financial agent, in cohorts with this granddaughter. She has taken some of my father's property (a pistol, in this case) and given it to him. I do not think my nephew should have anything of my father's. I asked for the pistol back but he never seems to be able to remember to bring it by. What legal rights do I have to change the Power of Attorney over to me or someone else more trustworthy?