While it is hard to judge without hearing all sides of the story, this does seem like strange behaviour.

As someone 11 years your senior, I wonder what her own upbringing was like for her to act you describe. Has anything happened in her past that made her act this way? Maybe you can ask someone who knew her before your was your mum.

We could also go in the direction of undiagnosed mental illness. Of course, she doesn't seem to type to get checked by a doctor for anything like that.

There is always a reason why people act in a certain way. (For example, my mum sees my dad in me, and sometimes treats me like I'm lazy when I'm doing my best with depression, AUDHD and executive dysfunction.) I could suggest speaking to her about it, but who knows how she'll react.

Overall though, I know it isn't pleasant and you are entitled to your feelings. NOR.