My mother is in assisted living in a facility and is abusive towards me. If I no longer wish to be her power of attorney, who could do it?

My sister dropped contact with my mother 6 months ago. I want to do the same. There is one niece that could take over. But who takes care of POA and financial things, funeral arrangements when there is no family or anyone that wants to? My mother is only 74 and is sharp mentally. She has arthritis that puts her in a wheelchair.