A friend of mine had her mum over from the states in august - she had gall bladder cancer and was dying
we saw her quite a bit, and she spent a bit of time with DS, who's the same age as her grandson
i decided that DS and I (2) would make her a card just before she flew home, obviously not to return
the card was simple - just ITNG stickers and scribble, but I wrote To (friend's mum), it was great to see you, and we hope you have a safe flight home, regards, MM and your little chum DS.
It kinda ignored anything beyond her flight home, but, as i know she was quite religious (we're not, but do respect religions), it carried overtones of "flights of angels" a la hamlet - as in flying off to heaven safely, and i like to think she knew what i was getting at
dunno if that's any help to you, but i know she appreciated the card. she died in nov
i think deffo ignore the cancer
last year, a friend's sister, who was dying of breast cancer, came to visit from the states (how many americans do we know? and why?) she was only 30 when she died in april this year
anyway...she came over with her mum to see her sister, and we all - me, dp and ds went for a long lunch just before they went back to california, they got in the car, after a slightly awkward moment when i just looked at her, obviously thinking "oooh, errrrr, what do i say, as you'll be dead soon", but i struck a different note and as they drove off, made the sign of the beast and shouted "catch you later, surf duuuuuuudes!"
which also worked (apparently)
you know this woman, so you can think outside the xmas/dying box to something a bit oblique, but friendly (IYSWIM)
hope it goes ok