Problem #1: I think, right now, the best thing you can do is be available for your friend. Let her know that you are a shoulder to lean on and an ear to talk to whenever she wants to or needs to. Maybe she'll want to talk about being afraid of her grandma's death, maybe about the cancer or the treatments, maybe she'll want to talk about some good memories, or maybe she'll want to talk about something that has absolutely nothing to do with "dealing" with the cancer. It doesn't matter, just be there for her and listen...don't push anything, she'll let you know what she needs.
And for you--this sounds like you're close with the family and will probably be an upsetting situation for you, so find someone to talk to yourself. Including us here at KH!
You mention that you know the Grandma's cancer is terminal but that your friend does not...maybe you should talk with the mom about that. I think it's the mom's place to inform your friend, you shouldn't be burdened with that.
Problem #2: Hmmm, I dunno really. You could go about organizing an emergency kit yourself to satisfy your own mind though.
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