100% correct. Back in the late 70s/early 80s I had an uncle, technically my grandmothers brother. He'd never married and she was widowed so they shared a house together. In retrospect, I think he was probably a closeted gay man.

Anyway, All through my young years he was a very kind and generous man. Smart too. He bought a Commodore home computer when they first came out and let me play games on it. He used it to write up a family history of everything he knew about our family's past. He also make a cookbook of all my grandmother's recipes. He printed both of those out and gave a copy to every household in the family. He had a shocking level of technological aptitude for a 60ish year old man in the early 80s.

Then one day he changed. I was young and nobody told me exactly what it was. Maybe a stroke or something. From that day on he was as mean as a snake. He'd rip into anyone over anything. Not violently, I don't think, anyway. But he'd scream and swear and slam things and be generally viscous. It was as if my uncle just died and was replaced by a scary, mean old-man who looked just like him.

While this woman may have been a bitch all her life, I've known plenty of healthy, young people who were no better than this. She might also have been emotionally disturbed and no longer the person that she was. Without more information, we'll never know.