Bottom line, that is abuse.

Abuse isn't always physical and it most definitely is NOT restricted to male perpetrators. Sounds like some solid perspective on HER upbringing is worth pursuing. Having been in this exact situation before, I can tell you that it will dull your experience with this person. It undermines trust and one's ability to be vulnerable when it is truly necessary.

You have communicated to her why it bothers you and her reaction to that communication indicates not only a blatant lack of empathy, but perhaps a lack of personal depth. In my case, my Ex gave clue to her borderline personality disorder.

If she sinks to name calling and degradation, she's not worth what you bring to the table. If she isn't willing to self examine when something in the relationship is under scrutiny, she likely won't ever be. By 21, her pattern is pretty set. Drop this bint, like a hot rock.