SteelAttack said:

Leo, as a physician, I can tell you that you are doing the right thing as her Health care Proxy. I've seen a lot of people go through unneeded suffering and prolonged agony because misinformed relatives wanted to do everything they could to offer him/her a chance. That's cruel. And you should not feel guilty about this decision. It's the most humane thing to do.
Stay strong.

 That is correct, plus she had Alzheimer before that. Even if she recovered from the stroke she would still suffer from the effects of Alzheimer.