I would not do this again  

Right, no point in writing such a letter, because such mothers not only don’t care, but as you state, purposely abuse you without witnesses, which shows they are conscious that they are doing wrong.

I too wrote a letter to my mother n sister, standing here as 55 yrs old woman recently met up with my mom.. Nothing changed.. I accepted it as it is what it is n I no longer need her approval, so in a way I wish I didn't write that letter, I should have just said thank you but... I'm ok where I'm at.. Go ahead with Yr lives n leave me alone.. Go no contact.. Full.. As no address forwarded nothing.. etc.. Honestly after meeting her... After 35 yrs n now since 3 maths ago.. I'm back in the grieving mode I'm trying hard to wash myself off of the meeting... I'm hating myself for feeling this way I'm working on it.. Layer by layer.. Accepting the situation. I offered the olive branch so to speak... She's in her world there's no way we could ever have that adult mother daughter conversation nor rship n that's that... Its OK..

Thank you for your insight. The lady that wrote Adult Children of Emotionally Immature parents says to keep trying. Good grief that’s such a waste of time! Wish I would have gone no contact at 17.

I've tried. It's pointless. These narc mothers don't care what we have to say. They already know. They would love to know they are having an effect on us. I'm sure they enjoy it. To know we are suffering. They want that power over us. Yes! My mother too waited until we were alone, and then she would let rip. So it's easy for nobody to believe me.