Don't agree with Dassie. Sometimes (as with friends) the pace of life and our own circumstances mean that we don't see/talk to others as much as we would like to. It doesn't mean that we don't care.
Put yourself in her position and ask yourself what type of card you would like to receive, if you were ill.
Personally, I'd send a blank card, with a pleasantly happy picture and put something like. "Dear ...... We are all thinking about you every day here in .......... and wishing you a speedy recovery."
It's positive and does not bring into mind the possibility of the failure of treatment.
Hope this helps even a bit!
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