I agree with the others, ignoring her (or blocking her, even) is the way to go. As somebody who was like this, I think by keeping open to and engaged with our children who are misusing us, is poor parenting. Why? Because we allow them to repeatedly play out negative, self-harming, aggressive, manipulative behaviors with us, and through us. We wouldn't have tolerated this when they were children. Why now?
I might even go a step further, and block her or not even read the texts. Think about it. 99.9 of texts are unecessary. They're for the convenience of somebody else. They intrude in our space without our consent. With a phone at least we have the option to answer or not. With a text there it is. If you'e ambivalent, and feel that this engagement with her is hurtful I might think about blocking her. If it's important she will find you by phone or through another relative. If she calls and questions you, you can tell her the truth in a kind way, such as saying, I am trying to wind down with technology use, so I am not reading or responding to almost all texts.
My overriding and underlying point is this: You have an absolute right to control your space, even virtual space, and you have an absolute obligation to think about rules and an environment and quality of life that is safe and serene FOR YOU according to your needs and wants. And you can impose this, just because YOU want to.
You don't have to justify yourself to her. You're the mother. You can come from whatever point of view you choose. If she harangues you or is unpleasant or demanding it is your absolute right and even obligation to take steps to insulate yourself, and if she crosses that boundary you have an absolute right to take it further. That's what I think.
Moreover, I am learning that many (or most) times I interact with my son as if I am the child, which is to say I don't start out thinking about my needs, my boundaries, my responsibilities. I look to him to do the right thing, from the position of a responsible adult, even though I have no experience of his doing so, and more than this, I NOT HIM AM THE RESPONSIBLE ADULT, the parent. This is insane on my part. I need to be the adult before, during and after the call which is to say, awareness of my motivations, clear about my intention, conscious about my boundaries, and clear about how I can conttrol and protect my space. I can't expect him to act in any kind of responsible way, bebecause that cedes control over my life.
I am seeing I can tolerate way more from my son, even selfishness and manipulation, or his crazy political views, if I stay anchored within my adult self, and don't expect him to act in a way that will please me, make me feel safe or gratified or any other thing. I think this has been 80 percent of the trouble we've had. That I abdicate being an adult.
I abdicate being the person who sets boundaries, and I abdicate being the person who takes responsibility for my own emotional needs to be met and protected. I abdicate responsibility to maintain safety. The result has been that communications with my son are a minefield to me.
I have set myself up. My son is just being himself.
