Update
My sister is doing fine and is in good spirits.
After her surgery, there was a group of visitors speaking loudly outside her room. It made the pounding in her head worse, and she screamed out, "Will you shut the **** up?! I just had brain surgery!" I told her that it was good that she could practice her social skills while in the hospital.
I asked what she's been feeling about all this, and observed to her that she seemed to be more relaxed than I've every known her to be. She said that she was blocking it all out, right up until her surgery. Now it seems that the painkillers and sedatives are muting some of her feelings about where she is with all this at the moment.
Don't know anything more about the nature of her tumor, and they're running some more tests today.
I'm truly blessed with a loving and supportive family. Including my in-laws, nieces and nephews. When I read about all the abuse, aggression, unrealistic expectations (demands), neglect, criticism, manipulation and control that so many people here suffer at the hands of family members, I am in awe at their exceptional capacity for compassion for other people.