Any threads on sons dealing with narcissistic mothers?

I live in Australia and visit every year usually staying at Mum's house mostly with my husband for four to six weeks with time out each visit. My brother and I experienced many of the cruel manipulative destructive behaviours as many have previously specified. Now our 94 year old Mum is living independently supported by paid carers morning and night and a housekeeper four days a week who does her shopping, bills withdrawal of money etc ( as neither me nor my brother could be trusted whereas if she pays an employee they are more easily manipulated). Lastly there is her rescue cat whom the home will accept back in the event of her demise. Mum is now imprisoning the cat and refusing to let it access the cat flap so it defecates in the kitchen behind the dishwasher. Mum is put into a wheelchair after a morning wash by carers and at night sleeps in a reclining chair in the kitchen so us unable to move at night. The housekeeper has made it clear she will not stay if Mum is being cruel to the cat which results in her having to clean up poo. When I was there and enforced the cat having outside access Mum tried to hit me with her walking sticks ( something she did regularly to me as a child). When my brother insisted the cat needed freedom to go outside Mum tried kicking him and tripping him up whilst screaming abuse and disowning him. My brother who lives nearby feels he is tainted by her verbal abuse and attempts at physical abuse yet feels by his refusal to go someone else would have to shoulder the extra responsibility. Mum lies refuses to believe anyone , is paranoid everyone is stealing from her whilst leaving her front door wide open for anyone to walk in. The carers have said her behaviour is deteriorating (previous carers have been bribed entreated cajoled and bullied to do things her way) and they are more able to resist her tempers and vitriol. I am now back in Aus. I have had a lot of counselling over the years- one attempt when I was in my twenties at trying to enable Mum to see my childhood as one of suffering at her hands instead of the halcyon days she had repainted at was met with, No wonder you tried to kill yourself if you believe that!' So I worry about my brother as well as where do we go next? If the housekeeper leaves she no longer has anyone to buy food bank pay bills etc. The carers and doctors tried to get her back into the electronic bed at night as she had leg ulcers but she refused and her decisions upheld that she was mentally competent to make them. Accordingly, we have no power of attorney and no idea of what to do. Incidentally, she is living in my sis in laws house whilst believing it to be hers. We have no idea of assets and the last time she called a solicitor round to talk about wills he refused to take any instructions from her. What do we do next and how can I help my brother from afar. Mum can no longer construct a full sentence so when I phone her I have little idea what she is saying. Any ideas? Fi