I don't know how likely this is, but what may have happened was that her husband compared you favorably to her. Or her son may have.

If it's gotten to the point, for you, that you want to swat at her at little, I think you should forgive her, then tell her about it and refuse to say anything else. Don't tell her what you're forgiving her for. But then, I'm occasionally petty and evil.

::HUGS::