Damn, so sad to hear, that's rotten luck
I'm confident she'll pull through though, even brain surgery isn't brain surgery these days.
My dad had a massive brain tumor when I was young, prognosis was that he would not survive the surgery if they tried. No one wanted to do the surgery as this type hadn't been done before in the country, but eventually they found someone willing to "give it a go".
Well he survived the first surgery and I remember him coming home with 1/3rd of his skull missing (seriously, a huge concave indent in his head) as they deemed it too traumatic to put it back in knowing they had to go back in a 2nd time.
They sent him home to be with his family because they figured he wasn't going to survive the next surgery.
You guessed it, he survived the next surgery and lived a relatively decent life (but on medication and not able to work) for another 20 years to see his grandkids (my sisters) born and grow up. In the end it was a stroke that killed him, likely because he refused to give up smoking after they told him it would kill him. That was 40yo medicine and surgery at work.