Mom is narcissist. I'm the oldest daughter and the scapegoat that has only taken care of her when she is sick then discarded. She was put on hospice 4 months ago for dementia. I'll spare you all the details that brought me here . But out of 4 months Iv only gotten help 3 weekends . That's Friday nite at 8 pm to Sunday at 12 by my brother. This time I decided to stay home instead of leaving. Mom acted so different . Wasn't demanding and was even watching football ,my brother got to sit n watch it as well and she didn't even poop at nite ! I have all the opposite with her! If she sees me sitting down she will look at me and say I want this or that at least every other nite she poops and gets it everywhere! My day start at 7 a.m and ends by 11 pm from working to feeding her,washing dishes ,sweeping due to she will get up and leave crumbs everywhere she walks . This past Sunday at 6 pm I went 10 min to walk my dog I come back she is sitting on toilet with 3 turds under her left side that she stepped on with shoes n sweats there nothing on her breifs or the toilet!! Is she doing this on purpose was my thought.I have to have her food as soon as she sits cuz she will say you haven't got my food ? Should I sit and give her some rules! Or is she just taken advantage of my kindness ??
In my humble opinion, and in answer to your questions, NO, it is not possible to create boundaries for someone who is suffering from dementia. They are no longer capable of self control nor of understanding boundaries. They suffer from disinhibition.
You may not be capable of caregiving. If not, and if you are POA for a demented parent, do consider placement.
Teepa Snow has very good and educational videos on YouTube reviewing all things related to dementia and how caregivers can have strategies to make interacting with them more productive and peaceful. You are now in Problem Solving mode every day. That's just how it goes with dementia. I wish you all the best!