Doesnt matter what I consider her to be. You just proved that "sociopath" was subjective by pointing out the fact that there could be two groups of people with different opinions on if she is a sociopath or not. There is a group that could assume she was indeed a sociopath and as in your example a group that doesnt consider her to be a sociopath.
The difference between us seems to come down to a difference in basic worldview - namely whether truth is subjective or objective.
Your reasoning works in your view because it holds to a subjective reality in which truth is pluralistic. It doesn't matter whether you think she's a sociopath because, regardless of the "facts", she doesn't and her opinion on the matter is just as valid as yours or mine. One and one might make two. It might also make one or even three. Who really knows?
Your reasoning doesn't work in mine because it holds to an objective reality that exists apart from our subjective experience in which truth is truth regardless of who believes it. It doesn't matter if she thinks she's not a sociopath because, regardless of anyone's opinion, she clearly meets the definition of combining a malicious impulse with an utter lack of empathy. One and one always make two. Anyone who says they make one or three is mistaken.
Of course, I'm aware that my view doesn't work in yours either. This is what seems to be the real tangent discussion.