I am never good at sympathies so if I am sounding like a dick I don't mean to...
I really hope she gets better soon! If she doesn't, it sounds like you two have some great memories to reminisce on, she sounds like she is an amazing woman with no judgment of your life's situations and has your back no matter what, even family like that is hard to find nowadays. I wish I had still had my grandparents around, it has been such a long time...my grandma passed when I was 9 and she was my most favorite person in the whole world.
I hope for the best outcome for her and your family 💕