So sorry about Mum.
As she is fit and active and independent than she will hopefully pull through. Yes many elderly die when a stroke gets them, but then the same elderly would probably succumb to pneumonia or flu.
Stroke is not the age thing that many assume. Strokes happen to all age groups.
Mum will not be the same person as before stroke. We all change, maybe for some the change is slight. Plenty the change is for the better, but it is impossible to be the same.
Expect endless sleeping for the next few weeks. That's the brain rewiring. And have faith that if Mum is destined to survive then she will.
I found it very hard to cope with visitors chatter. I was far too busy trying to get words in and out of my head. But we are all different