This is a really huge topic, I think. It hits so many different fundamental impacts of having an N parent. It is helping me just to read it after all these years where all my perceptions have been just in my own head, in Silence, and have never heard or seen anyone discuss these things. Gaining Strength, many things you have been writing are hitting me like bolts of lightning.
The way I see them is this. Maybe it is from having no empathy (maybe that is the retardedness?). The never see what they do to others, what they say to others. But they feel the impact of a pea under 10 mattresses or the brush of a feather when it happens to them. There is no reciprocity in it. You could sit there face to face and if every time she slapped you, you slapped her right back - you could do it all day and all night for a month and she would never understand that the hand slapping her is a reaction to the slap she is delivering and the slap she experiences will be hateful and persecuting! And the slap she delivers will always be justified and right.
Ami, it blows my mind that your mom admitted to NPD, though it makes sense that she would do it for tactical reasons as you explain. But that she even would means that you are showing strong power right now and she is responding to that. I hope it doesn't freak you out that you are in power/ "In Power"/ empowered right now. You are ruling. You have the upper hand. I hope you can let that experience continue to be with you and not react against it strongly, because you need to be your own power as is right and be in your own authentic power. She will try to toss you if she can. She won't let that stay if she can help it because, this is my own thought based on knowing my Dad, Control is everything to her and is the fundamental core of it all. I see a lot of different opinions on what is the core, but before I knew what NPD was I saw the core in my dad as Control, Control even if it kills him and lays waste to everything good in his life. Control at any price.
Any price. And control of the uncontrollable - not themselves - because they cannot see themselves and cannot even see their own actions (so how could they control them?) but others, the environment. It's impossible really. It's nonsense. It's futile.
By the way, it's really horrifying that she is a therapist, speaking of destruction.

If it were me, I would avoid her now and for quite a while, because you are in power and she will be seeking an opportunity to change that and will be sharpening her weapons and seeking your vulnerability.
I want to say that I have made a certain mistake many, many times. The mistake was believing that if I change my dad will change. I think if I counted the years I made this mistake - it would be from about 1985 to 2005. That's some sad stuff. Every time I learned something new from the ages of 15 to 35 I took it back. And got smashed. Finally I understand why I always felt so much pity for Wile E. Coyote, who everyone can see is going to land underneath the boulder or crash into the canyon
again, but still he tries.

There's really no excuse for all the water carrying I did in the years 1998 to 2005 either, because by then I knew better or was learning better in therapy - but even then I took the insights back. But by then I thought letting go of the outcome might change the outcome. The no-control control approach. A no expectations expectation. He is exactly the same and if I acted the same he would be the same as he was. But I act different now. It doesn't mean he has changed, but he must change the way he acts with me because my strategies are much improved and I finally understand that strategy must be applied here. Like a general surveying the ground, like a card player planning to shoot the moon
There's a lot more to say but I'm off to visit my little cookie at daycare. I want to talk about the double bind of sabotage/paralysis - this is where I have been and in ways still am. I'm assailing it with everything I have.
P.S. Ami - the ancient Egyptians believed the heart was where wisdom and intelligence resided, not the brain. They would think everything over with the heart as you do.