Love the self made gift basket idea.
This place is killer, if you are looking for items to send her:http://www.risingheartsbakery.com
Also maybe you could include a book on gluten free recipes or gather a few great gluten free recipes of some of her favorites. There is a gluten free alternative to almost anything these days. She can see it as a great loss or a great new adventure. I haven't been able to eat gluten in over 3 years, I really don't miss it or how it made me feel. It may be tricky at first, but it can be a really wonderful change in her life. You are a good friend for supporting her, FYI. You get a a gold star, in the friend column!