This is a small thing, but whenever my mom is in the hospital (she has metastatic melanoma) she complains that it is so cold. A shawl, little jacket or sweater can go a long way. It is something to keep you warm and cozy while you sit up in the hospital bed. Also, any pictures of family or whatever makes her happy can help. Oh, and sometimes the hospital food isn't so great. If she has an appetite and isn't on a restricted diet, maybe a favorite treat from outside the hospital would be nice. We always brought my mom chocolate shakes.
As for fear, I would advise just let her talk about it as much or as little as she wants. You can just ask her if she wants to talk about it, and respect her answer if she says no. Each day will be different; allow her the space to be up and down, confused and scared, strong and loving. Just knowing that you are there, and are willing and strong enough to listen to whatever she is feeling in the moment must be such a comfort to her.
So sorry. Wishing your family the best through this trying time.
-M.