My heart goes out to you and you are correct in the amount of support you can give. I am not proud to admit that, like many victims, we are drawn in by the 'I'm in need of help' routine. And my family did what you are doing, except they didn't know it was sociopathic behavior, only that he was doing some things that they were extremely concerned about, as were they concerned with my growing distance from them and a fake smile replacing my former open trusting fun loving self. They did an intervention right before the wedding which in turn caused me to run. Right to him. I hadalready been fully groomed with fear of the unknown, unexpected rretaliation that seems to be the basis of a lot of folks living with sociopaths.
Stay in her life, keep loving and praying for her. You are doing great.
I knew 'all' about sociopaths too. I have a degree in psychology/abnormal psychology, worked in the field for over a decade. Should know better right? Problem is sociopaths rarely seek treatment, and when they do its for reason of manipulating and gaining more 'support' in some personal gain. In all my years I had never had (knowingly) a sociopath in my professional care. Psychopaths, sexual deviants, etc, yes. Oddly when going back to read up on the disorder I found the glaring reason why. Sociopaths are aware and premeditative in much of their (dys) functioning. The folks I treated over the years had little control over the behavior but could fully admit they did it and wanted help. Sociopaths use that claim for their control need, not to get help. If it helps to state this to her, subtlely or however, please do.