Sounds to me like you nailed it Levi. She seems to be putting you in the same box with the other guy and her old coping mechanisms are coming out.
I still have times when I say or do something totally unexpected to my husband, when I have to tell him that it's not him that I'm reacting to, it's my old baggage, and have to apologize for my behavior. I usually explain to him what the baggage was and that I don't expect him to change his behavior, but I want to let him be aware of what button he pushed.
Sounds like she's not aware of even having buttons, forget being able to work around those buttons. And it sounds like you're starting to resemble a great big button for her. I wish you much luck in working this out with her.