Having a manipulative parent is nothing new. It's how and when we recognise it; usually as we get older and our life experience grows. Yes, it hurts when we realise we aren't the favourite child. Often it doesn't take a pandemic or lockdowns to bring the realisation to the fore.
Daughters who walk away often feel guilty. Maybe all to do with caring and nurturing. However, we have our own lives to live and don't see the situation changing. After walking out on my mother over six weeks ago, saying I wouldn't be treated badly anymore, we were finally in close proximity at a family event yesterday. Told her it was pointless my brother doing 10 mile round trip to pick her up when I was 2 miles down the road. She was appreciative. From things she said, her new shopping arrangements weren't going so well. My sister-in-law has apparently set up home delivery. So favourite child hasn't really stepped up to the plate, as the saying goes.
She's always been difficult, stemming from how her mother treated her. At first I thought it was her failing health, then realised from her comments that it wasn't the result of old age or dementia onset. Very sad!