Paranoid schizophrenic mother. They can be great mothers until their children get to the age of reason. Then they will either pick on one child to hate (normally the eldest same sex child) or hate them all and pick on one child that they think is on their side. The 11 yr old was lucky that he was the favored one.
I would agree with you...some element of paranoid schizophrenia at play here. Stress of being home with kids constantly because of the Covid-19 business probably in the mix as well.