This could be my mother (and her childhood experience exactly) She was also evacuated whilst her younger brother stayed with her mother, which she was always bitter about - but she went to family in Ireland whom she knew, so not total strangers.
I recognise the volatility too. I grew up never knowing what sort of mood I was going to be dealing with. She could appear to be very loving, almost suffocatingly so, and then without warning lash out physically and verbally.
Definitely very patriarchal, although that might have been her upbringing too. Men did the ‘real and proper’ work, women were there to look after the home. Women who were ambitious were ‘either lesbians or man haters’! She openly said that if she were an employer, she would actively promote a male over a female. She would accept whatever my DH or DS told her but dismiss my or my DD’s opinions as frivolous and irrelevant.
Likewise like your mother, if she fell out with anyone, she was always the ‘victim’ She could never see the trend or the common denominator. Having said that, distant family thought she was wonderful; witty, fun, hard working and the perfect woman and often told me how lucky I was to have her as a mother!
Both of ours sounded scarily similar!