The above comments are certainly interesting. I think (JMHO) that people still have a hard time imagining a woman can be a cold blooded killer. A woman can kill just as easily as a man. It doesn't mean to me that somehow only the female in the equation had something happen to them that was so traumatic that the fault necessarily always needs to be spread around. I tend to look at all sociopaths as a group and not just by sex.
For many, there always has to be a reason, a poor relationship with the family, underlying illness (mental), too much pressure...etc...it is very apparent to me even in TM's comments about KC. TM says that KC was nice, etc...if only...the if only, I think is where the sympathy comes in.
Where grifters and others tend to prey on that is that one point: If only. Not one person made KC do what she did. KC was very much in control of what she did and her behavior after the fact (her lies, stealing). While it is hard for a lot of us to accept...you have to take out how you might feel and imagine someone who had about as much regard for her daughter as you might any other object that you got enjoyment out of but once you became bored/annoyed with it you moved on to the next thing. JMO again. I am only trying to fill the shoes of someone I can't possibly hope to understand completely. But it all fits. The jealousy. The consistent lying. The laziness. The boy hopping. The stealing. The inability to make anything truly stick. KC was adrift and going with the moment. And if for instance something got in the way of that particular moment in time...JMO.