What about non-pen&paper puzzels? Like these.
They’re small, nice to fidget with, and don’t take a lot of concentration.
Thanks for all the input, guys! I am reporting back to say what I ended up getting.
I really liked the idea of the gift bag, so I just got Paula lots of little things for in the hospital, a.o:
- the puzzle book + pretty pen!
- Body Shop hand cream
- Body Shop lip balm
- jar of sweets, picked out the ones I think I know she likes
- a pretty patterned scarf
- a really useful clip to clip your bag to any table, I have one myself and love it and she is always trying to find a good place to put her bag at the hospital
All in a pretty bag with a chrysanthemum stuck in there, too. And then… inside that another bag! Because we talked about how she missed Will, I made them both a Romantic Hospital Date Night Kit. Be warned, it’s exactly as lame as it sounds. It had two electric candles, a little bag of fake rose petals (yeah, I know!), two “love crackers” (like Xmas crackers, but errr “love”) and a bottle of children’s champagne and two champagne glasses.
She was excited but I didn’t stay to see her open it all. Also, Will is doing a lot better which is really great. 
Many thanks for all your great suggestions. To those of you who spent time at the bedsides of loved ones: you are angels! I hope everything is better now.
Well done Gracer, they will never forget your kindness!