A friend who went through chemo last year recently told me that she really loved things like Edible Arrangements (or just cartons of cut-up fruit from the grocery store--no need to be fancy) because she and her family could snack on them immediately without doing any prep work. She didn't really enjoy getting cut flowers (because they died) or live plants (because they need to be watered), and books were too much for her to focus on sometimes. Trashy magazines, iTunes gift cards for her iPod, and healthy snacks were the things she liked most from our care packages.
Gift cards to restaurants that deliver to her! Or grocery delivery gift cards. Amazon is good too.
Cancer is expensive, so anything that meant i didn't have to spend our money and made our life easier was really helpful.
All of this. Not having to make dinner is amazing. This might sound stupid and seems way out of left field, but we bought my H a bunch of these portable vomit bags and Chris carries them around constantly so that if he does get sick he doesn't have to worry about where a trash can is or getting to the toilet in time. Honestly, he has been so uncomfortable that there isn't a whole lot that he enjoys. The drugs that he's taking make him really sensitive to cold so maybe a nice throw for her to use would be nice.