Welcome Flower. Your story of your discussion with your mother conjured up all kinds of flashbacks to when I had left home and every time I would stop by to visit, my mother would try her best to get me to return to the "truth". I tried one time to reason with her and like your mom, the grooves in the cranium from years of JW conditioning were too deep. Whenever I would expose a fallacy of logic to her she would just get mad. Of course back then there was no apostate sites, hell, there wasn't a computer!
Anyway, I commend you for trying and hope that you will be able to show unconditional love to her, which I suspect you are already doing. Even if she never addresses the cognitive dissonance needed to swallow the borg line, you will have kept yours and her dignity intact.
BTW, if that is your picture, you are one beauty, and I presume that cutie in front of you is your son! You are both a sight for sore eyes!
Hope Waiting don't catch me flirting!!!