My Uncle has POA over my grandmother but she has dementia. Is the POA valid? My uncle has started changing all my grandmother's assets in his name and cashing in her life insurance policy. I feel he is going to sell her house next and put her in a nursing home. Is their anything I can do to help her? She doesn't even know what is happening. When I said something he told me he has POA and I have no authority to say anything or do anything.