So I emailed her today. I haven't been answering the phone (haven't talked to her in two weeks) and she keeps calling and calling and emailing and it seemed unfair to say nothing at all. I am seeing a counselor about this stuff and she said it was fine to call or not call, email or not email. Somehow today I felt like I had to tell her something. I decided to email her because I can't talk to her on the phone - I wouldn't say what I needed to say and I would probably back pedal and end up feeling worse and like a lame fucking liar. Regular mail is too slow and seems so serious and it is so nice to get a letter usually so it seemed extra awful to have it be a bad letter.
yes, email is cold and impersonal, but hell, that is nothing new with us, so I emailed.
I discussed it with my husband (he read a draft version) and then sent it.

I thought I would feel more of something, but so far I don't. I set my email up to forward any messages from her to my husband (so he can tell me if there is something I actually have to contact her about and such) and she has a special ringer on my phone so I will know not to pick up (I wish I could set it to silent, but you can't do that on my phone). So I won't have to deal with direct repercussions. I plan to tell my aunt (only other family member we are both in contact with) what I have done and leave it up to her what information she wants to pass in either direction, including whether she will tell my mother that we will be in the area next month. I want (so badly) to be able to control what happens next, but I can't so I have to get over it.

In my letter I tried to be both honest and not attacking, just factual. And for the record, she does have actual documented mental problems in addition to her lack of parenting skills.

Here is (slightly edited) what it said:
Hi,
I am sorry I haven't been in touch with you by phone lately. I know it's a change and I know it is bad timing for you with your current health situation.

I have been thinking about some stuff lately and it seemed better to not discuss it than to discuss it in the wrong way.

I was very uncomfortable when you got mad about B(my 3 year old son) saying XYZ (wouldn't make sense to y'all unless I explained it at length). And I felt very uncomfortable when you told me that W(my husband) was going to leave me even if he didn't know it yet. I think both things brought up feelings and things that happened in our past that I don't really have the tools to discuss or deal with right now. I have agreed, or seemed to agree, with your take on a lot of things and how they happened in our past, and it isn't working for me.

Recent discussions about family members, or family situations, have left me feeling uneasy, or worse.

None of it is stuff I know how to talk to you about, I think our experiences of our mutual past were so different that we won't likely come to the same conclusions no matter what.

I love you and I care about you and I know you love me and care about me. I need some time to process this stuff on my own - a break. I don't know how to talk with you and avoid talking about the things that make me so uncomfortable.

I wish I could be there for you to support you in your time of need and sincerely regret my inability to help you.

I am seeing a counselor right now, so that should be helpful. My great hope is that I can process the things I need to and unlimitedly have a relationship with you that will work better.

I am sorry I am not stronger and more "together".

I love you.

(my name)