Greedo,
I hope she comes through this well, she needs to stay positive and fight it. Don't worry about odds that's only statistics.
My brother in law had a grade 4 glioblastoma brain tumour removed last year and the doctors were really pessimistic about it, saying that there will have been some parts they couldn't remove which would act as seeds and it will grow back, basically saying its terminal and really all they can look at is treatment to prolong life but its only a few years at most.
None the less he's taken the attitude that he will beat it. He finished all the radio and chemo therapy well over 6 months ago and now the consultants are using phrases such as making significant improvements..... They aren't calling it remission yet but they do seem to acknowledge that its a possibility now.
Just like your friend he is one of the nicest, fairest, decent person that you could hope to meet.
She can beat this, all you can do is support her as and when she needs it.