My mum was a good mother (albeit controlling and enmeshed, but she had her reasons) when I was a child. The problems arose when I was an adult.
My sibling is 10 years the older, and has always been jealous of me. Could never cope with me being the centre of attention, ever (eg I was bridesmaid for a family friend, she wasn't impressed so decided to tell our mother she'd been raped. She later admitted it was all lies, but meant the entire reception was spent with the rest of the family outside consoling her, whilst I was left on my own confused as to what was happening.)
This meant that she couldn't cope with me being treated as an equal when I turned 18, so my mum didn't, going for the easy option.
I was made responsible for her feelings ("Don't do/mention X, it might upset her!") whilst no such instruction given to her. If I was then upset mum would dismiss my feelings, and actually told me I hadn't been upset hours after she'd seen me crying.
The crunch point was 2 years ago. I had a baby at the start of Lockdown, so missed out on the whole showing off my baby to friends thing that I'd waited so long for. Eventually managed to visit my mum at nearly 5 months, and looked forward to seeing people. I needed the time for me, and stupidly seemed that, for once, the time would be about me.
I was wrong. My sibling visited, and announced she was coming over every day. I was upset (much to my mother's surprise, though anyone who knows anything about my relationship with my sibling would have expected my reaction). Every day I was told not to spend too long with friends (some I was "allowed" to go and see, but I had to be sneaky about it - seeing friends was the whole damn point of the week!!!!!). I was also "supposed" to let her do x, y and z with my baby. Friends organised afternoon tea for me, my sibling dominated and I barely spoke 100 words in two hours.
I cried myself to sleep each night which my mother knew about. I also utterly broke down in front of her three times, to which I got responses such as "I didn't think you'd be this upset," "Stop going on about it," "You're upsetting me!" Bearing in mind that if I'd been my sister she would have been tangling herself in knots not to let my sister be upset.
The crunch point was when, having said I'd message sister to asked her not to come over on the last day, meaning I'd be able to pack etc with no rush, let baby nap before leaving, and have something to look forward to other than getting home, my mother looked me in the eyes and said "You can't do that, she might be upset!"
So it's fine for me to be utterly heartbroken for a week, but heaven forbid her precious first born is upset over one day.
That's when I realised I could never treat my child as she's treated me, and thus I can't believe she loves me. I'd take pain and argument for my dd any day. To her I'm a sacrificial lamb. I didn't speak to her for two weeks after that, and she asked me why. Wasn't it obvious?