As a recent cancer survivor myself (diagnosed in June, 2008 with Hodgkins lymphoma the day before my son's second birthday and just before my daughter was 11 weeks old), I have a different perspective.
All thoughtful gestures are appreciated. But, it's really a personal thing as to which are most needed and which will go to waste (unfortunately). A lot, too, depends on what her treatment regimen is. If she has chemo vs. radiation vs. surgery or a combination of any of those, her needs will be considerably different.
For us, meals almost always went to waste. My husband is a picky eater, our son was still quite young, and I had little appetite when being treated. We were OK with sandwiches, scrambled eggs, and cereal when I couldn't cook. But, gift cards to restaurants were VERY welcome.
The NICEST thing you can do for her is be there. When you're facing a possible life-treatening illness, you need to feel that people want you to fight. I just wanted people to spend time with me. Call, write e-mails, send jokes, send silly carepackages once/month, send your favorite books, get her a magazine subscription that has nothing to do with cancer.
Wear a LIVESTRONG bracelet in her honor, and don't take it off. Send her 10 to give to people who want to support her. Send her a LIVESTRONG shirt.
Donate to the Susan G. Komen Race for the Cure in her local area. Start a team and travel to do the race with her the next time it's in her local area.
Get her the book, "Crazy Sexy Cancer" (it can be risque in parts, just a warning).
Just BE there for her. And be there today, tomorrow, 3 months from now, 3 years from now. Survivorship was one of the hardest parts for me (along with losing my hair). Most people don't think to ask about how cancer still affects me, and I think most people have stopped caring in many ways.