Is there such a thing as a selfless abuser?

Every resource about abusers seems to name selfishness or self-centeredness as a key trait. The person that I was in a toxic (one of my close friends believes it was abusive) relationship with (23F) really and truly cared about others, including me. She took care of her elderly grandmother, went out of her way to help her mother (who was emotionally abusive to her as a child), and always seemed to be thinking about other people and how to help them. Now, she also was pretty entitled when it came to me, and expected me to always be available to help her and her family, even if it meant skipping my grad school classes or bailing on plans with my family. (Often if I declined to drop everything for her, I would get yelled at, guilted, called names, etc). Her explanation for this was that she would never ask anything of me that she wasn’t willing to do for other people. And it’s true that she never really expected anything in return from her family for helping them. So, can someone be emotionally abusive/manipulative but be selfless (without any ulterior motives) towards others? Or is this a sign that I’m misinterpreting the dynamic of the relationship?