I'm sorry to hear what you're going through SS. I'll just add that lying is a tool of the N. One of many. Manipulation requires the occasional, or not so occasional lie. When it's an aquaintence or co-worker or stranger, you can phase them out of your life, but when it's mother, it can instill in one a rage (or a depression, I suppose) so intense it can hardly be contained. And that is precisely why they do it. Like Leah says, it's just good, old-fashioned, gaslighting. She wants you to think that you are the crazy one, that you are the unreliable one, that you are the incompetent one. She's a con-artist, therefore, her lies, to her, are real. Con-people have the abiity to believe their own lies. That's why you feel like you want to hit something, because the lies fly in the face of what you KNOW to be the truth. Try something different. When she lies, you smile at her. You give her that look you would give a toddler making his/her first attempt at a lie. Patronize her with a "there, there.." and a pat on the head. Let her know you know she's lying with the strong confidence that she is unable to rattle you with her lies. Take the bite away. When she's lying and you can't prove it, begin to give her that same look, maybe even do the finger shaking motion that says, "oh you little rascal, you, what are you up to again.." and make it look like she's the incompetent one. The more confident and patronizing the better. I think this would cause her to lighten up on the lying because she's not doing it to empower you, she's doing it to frustrate you. Don't allow her. Personally, I would go with NC. Who has time or energy for games and tests? Take care and best to you with whatever decision you make. Oh, and I'll just add this quote from a book mentioned in another thread where the lying of the N is described.
John Steinbeck on the manipulative lies of Cathy Ames: (major female N character of East of Eden)
“Cathy was a liar, but she did not lie the way most children do. Hers was no daydream lying, when the thing imagined is told and, to make it seem more real, told as real. That is just ordinary deviation from external reality. I think the difference between a lie and a story is that a story utilizes the trappings and appearance of truth for the interest of the listener as well as of the teller. A story has in it neither gain nor loss. But a lie is a device or profit or escape. I suppose if that definition is strictly held to, then a writer of stories is a liar—if he is financially fortunate.
Cathy’s lies were never innocent. Their purpose was to escape punishment, or work, or responsibility, and they were used for profit. Most liars are tripped up either because they forget what they have told or because the lie is suddenly faced with an incontrovertible truth. But Cathy did not forget her lies, and she developed the most effective method of lying. She stayed close enough to the truth so that one could never be sure. She knew two other methods also—either to interlard her lies with truth or to tell a truth as though it were a lie. If one is accused of a lie and it turns out to be the truth as though it were a lie. If one is accused of a lie and it turns out to be the truth, there is a backlog that will last a long time and protect a number of untruths.”