Looking for a working definition of "kindness"

So, my mom called me last night and she sounded so sad. I really have no idea how to deal with that woman. I mean, she raised us and we are perfect ergo she must have done SOMETHING in a correct enough way for her to be able to replicate her success several times over. But she's so disillusioned and bitter and ungenerous right now. I can't imagine that she was "always like this" but I also can't remember a time when she wasn't to some extent. Seriously, the woman has none of the skills it takes to exist in the world she wants to exist in -- socially, I mean. She's loud, she's stubborn, she fails entirely to see any of her own complicity in situations that "for some reason" turn bad -- she's the opposite of the kids she raised. I seriously don't get it. I also don't get why I can't just be nice to her. I mean, I'm doing all this "basic acceptance" crap around really just getting that people are just people and that every single human being (even the very obnoxious) have some aspect of them spun in a way that I find admirable but I find it INCREDIBLY difficult to just freaking be nice to the woman who introduced me to the world. And believe you me, she needs it. I think it's a love thing. I get this massive amount of love from people and the world and my kid and I think it makes it easier for me to love back. My mom's pretty cut off. I mean, my brothers and I try to spend as little time as is humanely possible around her lest we go insane and start with the shouting, she's hasn't had a "significant relationship" since the 80's and everytime she finds a job where it seems like people "need" her (like her teaching) she gets fired because she annoys the hell out of her supervisors. I dunno. I was listening to her last night and I kept thinking "Well, I seriously doubt that this latest notice came completely out of the blue. I mean, seriously, You're working for a huge bureaucratic organization, there are probably multiple levels of warnings you have to get before you can be let go. You probably just weren't paying attention because you never pay attention!" But instead, for probably the first time in my adult life, i just said "I'm sorry."

God. I hope like hell my kid is better at this than I am.