Thanks for asking the question.
I am Dr Adil.
After going through the details of your question, i noticed that your patient has many problems, she has mitral valve stenosis, prosthetic valve, i presume that mitral valve stenosis may also caused her atrial dilatation and atrial fibrillation
that had lead to the embolic stroke
Now she also has sub-dural and sub arachanoid hematoma
So these are so many problems, one correct one problem at a time, and all these problems require surgery and for surgeries and anesthesia
one needs a good and sound heart and she is also on mechanical ventilation
, and long term mechanical ventilation also compromise the function of lungs.
I am not seeing a good chance of her recovery.
But in medical sciences, miracle do happens.
I wish her well and hope, may she wake up soon.