How much more can my mother's weak body take?

Friday morning at 3:30 my mother had a light heart attack which at first was thought to be another seziure. She was taken to the ER and admitted into the hospital. Her hemaglobin was low. So, they gave her a blood transfusion. Her UTI has returned and she has a skin infection, cellulitus.
I was talking with a nursing home nurse who knows my mother. She wonders how many more seziures and heart attack that my mother can endure in her already weakend continue, lack of doing anything PT attempts to get her to cooperate with; when you take into account several years of seziures pluss a heart attack before she fell and broke her hip and went to the nursing home. The nurse said she could tell that everytime my mother came back from the hospital that she was never quite the same and declined more mentally, etc. than before.