My first suggestion would be for you or her to find a book that talks about the different types of flour and how they differ from wheat flour. I have heard from a couple celiac people that it took them a while to figure out the right mixture of flour... We found a book that talks about which combinations of flour to use etc. So, IMO, no matter which book you look at... that would be a helpful feature of the book.
The Allergy Self Help Book... we have this one; there's great detail about the types of flour and how to use them for baking, breading, thickening, etc.
The Wheat Free/Gluten Free Cookbook for Kids and Busy Adults... recipes are good basic recipes for quick everyday stuff.
Kid Friendly Food Allergy Cookbook... includes all kinds of allergen free recipes, each recipe lists how to substitute whatever ingredients you need to fit your food sensitivities...
The other thing to mention to your friend is to be wary of her MEDICINE ingredients. She probably already knows this... but it was a suprise for us. It is likely a good idea to call the manufacturers to check the ingredients. Also things like natural flavors can have it in there (although now it's supposed to be listed), and in caramel color? or flavor? I have heard that Gluten is used in probably the widest variety of products...