What does it mean when 83yr old mom with dementia, wakes up and says she died?

Maybe it was a good dream.

I was also going to say maybe a bad dream.

never mind :) was going to say was a bad dream...

id delete if I could

When people have dementia, we say their brain is “broken”. What does it mean? It means that the disease is making her hallucinate. Whatever meds she’s on may be giving her strange dreams. Don’t argue with her. If she doesn’t seem upset about it, just say, “Oh, you did?” And leave it at that.