Look, this is all about her And her problem, you need to get your head round that Do not try to overly engage her or suck up to her, it willl just bring the bully out in her. So do your job, interact where appropriate , be polite and professional and that's it. Please, for the love of god, don't go getting all needy with her.
I'm not sure about the hard wiring stuff on us caring, I don't give a shit unless it's someone I love, care about or like. Even then my reaction is normally "what's your problem". People tend not to be rude twice. For the simple reason they know they will get called on it and it will take them awhile to come back from.
Generally I find when I witness something like your incident, the more you let them away with it, the more they want to treat you like shit. It's simple bullying behaviour.
The only thing you can control is your responses. Simply do as above. Polite, proffesional,engage only as appropriate, get on with your job.