You raise a very interesting point.
As John rightly says, stroke changes emotions. Sometimes for the better, but nearly always different.
The next thing is that Mum is not the Mum she used to be and she will not go back to the Mum you once knew. So please don't imagine that her nasty reactions will necessarily go away.
It is early days and her emotionality needs time to settle.
I have found that the most difficult thing in this long recovery is trying to fit back in to society. I am not the same person, but I remember how I used to react and I cant do that now. In my case I was outspoken and now I am very quiet.
Only another stroke survivor can understand what Mum is going through. And its logical that only another family can understand what its like for you.
It is not good that she keeps saying she has had a stroke. We need to eventually accept that our disabilities are real and permanent or semi permanent. And we need to then live our lives as best we can. We do not fully recover. Part of our brain is dead and it does not regrow.
On day one, I realized I needed my wife and that she needed consideration. So I insisted she spent a couple of hours every day, away from me. Then, after a couple of months, that she spent a few nights away. This keeps her sane and it helps me to be independent and allows me to sort my head out.
There is a level of behaviour that is not acceptable. Stroke or no stroke, there is a line. I am not saying Mum has crossed the line and really its up to you to fix that line.
You can not make Mum better. The Doctors can not make Mum better. She has to do this herself.
Finally, the stroke survivors I have come across are not nasty nor inconsiderate. And they do appreciate the help given to them. But every stroke is different
I do sympathize