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I keep doing this - hitting the submit button before I'm ready.
As I said, I'm learning to deal with her and her moods, and whilst I don't particularly like my sister, she does back me up when Mum is clearly in the wrong, so that's a help. Sis doesn't criticise half as much as she used to, probably because she knows how futile it would be. I guess I need to take away the emotional attachment to mum as I have with Sis.
I understand the need not to blame Mum, especially when she's had problems of her own, but I think the frustrating thing is that then that leaves me with no-one to blame, and I refuse to blame myself. I used to do that, but I know now that it's not my fault.
LeChat, I will look out for that book and some similar titles. Maybe they'll be able to offer some coping strategies. and tombrandy, I think you have a really good point there. Being myself and casting thoughts of parents to the wind has allowed me to show people the real me, and they have become valued friends, so maybe I should do more of that.
I'll let you all know how I get on, and thanks again, all of you. It's been really good to get this off my chest.