Well, what can I say!
My brother asked to meet for a chat. This happened yesterday, he bought me dinner. It was a "cards on the table" talk about mother and the detail stays between us, not even for discussion with my aunt. What I can report is he and I agreed on a lot of things.
He's also been on receiving end of her unacceptable behaviour, mostly when he phones. Terminates the call, not hanging up. I believe him as so much of what he said matched with my experiences. We also talked about historic issues which could have influenced my mother's unacceptable behaviour. There were also some issues he knew nothing about or only had her versions (which weren't true). She's been playing us off against each other, just as her mother did...
He was happy for me to fill in gaps or relate things that he hadn't experienced. There was no blame, instead he wants us to see if we can do more for her without jeopardising our own lives. But, in his words, "it will never be enough".
He also observed how she's alienated her neighbours and has pointed this out to her. He knows nothing will change.
He wasn't too happy with out aunt's comments to me, but recognises others are entitled to their own opinions.
My head has stopped spinning. I feel a great relief that he's witnessed the poor behaviour and agrees it's unacceptable. Result!!