How can I tell when sister is coming/ going from rehab center?

Hello,

I currently wrote about the 'Rainbow Rock' situation. Well, my mother is currently in rehab from a neck and spinal surgery. Basically, I asked her yesterday if she wanted me to come, and I'll also come by for Thanksgiving . She asked I come for that day and to please stop by her house first to get some of her things. I said ok, and was glad to get some rest after getting off work early and having to go to a coworker/friend's funeral that morning. Exhausting situation, to say the least! However, she called me last night to say something like, 'Well, well, guess who's here...!' It was the troubled narcissist sister with the hand problems. First, I went quiet because I was laying down and surely didn't need any nonsense. I just said, 'Good.' Didn't know if she meant there there, or in town, so I said after some silence, 'She's there right now?' And then the sis goes, 'Hi...', so I said 'hi' back. My mother (another narc), acts cheerful by stating now I didn't have to bring her stuff, as the sis would do it. I said, 'Good, because I could use some rest.' My mother says rather quickly, 'You're still going to come, right?' I go something like, 'It would take me some time. I had quite a week and need to rest.' My mother goes that was fine, 'As you can see, you can come late.' (The sis was visiting late). I said something else to that effect, said, 'Enjoy.' And got off the phone. I felt that fog coming over me that narcs tend to make one feel. Couldn't think at first. But thanks to all my research and therapy, I thought to just get my rest and I'll let the mother and grandmother know I'm not coming at all on TD (this after around 10 years of being there for them on holidays and hospitals). Called the next morning and let them know. They knew I wasn't planning on doing much; said so before that. Was only going to stop by the rehab to bring my mother's stuff (not too far from me); and grandma's a little further via car. Couldn't do all that on top of feeling under the weather, especially after my coworker/friend's funeral. However, instead of understanding, the mother asks if it's because of my sis? I said that I already told her before it can't be both of us at the same time. She should understand this, as when my sis attacked some months ago, she was there herself. This 'girl' put us all in jeopardy because I was driving and my mother was in the passenger seat with her neck and back problems. What if I blacked out or ran into another vehicle, or a person? Because of keeping my head, I not only carefully pulled over, I got out and had to teach her a lesson. Didn't speak to them for weeks, until I told my mother (who was being pushy in me calling her) to not ask me to go anywhere with them again. I'm only there for her and my grandmother for emergencies. Do you really think just because it's been months, that goes away? I can't trust her; period. Told the sis at the time she is abusive and there is a pattern there. You know she couldn't face the truth. But it's terrible when my mother is helping her not to; and actually instigates these situations.

I asked my mother how long she said she plans to be here, and she claims my sis didn't say. And don't even know if she already knew she was coming to town, instead of claiming she wanted to 'surprise' her. I said it was strange, myself.

At this point, I just want to find out a way I'd know when she was coming and going, to avoid her. I can't count on my mother nor grandmother. They both keep hemming and hawing about it. My mother even started gurgling when talking! This is so beyond. And I have too much on my plate to worry about adding to it.

Oh yes, hoping all had a Happy Thanksgiving. We certainly deserve the one we want to have!