About the DVDs, I'm guessing you're referring to the Siggraph Training series? I'd get both because they each have unique tutorials. The tech ref guide is what it is, very technical but it is an excellent reference for advanced users. The Art of Animation:Master is a must have for beginners who are not yet familiar with the program.
Sorry to give you so many choices, but if she is a beginner then I'd start wth the TAoA:M.
I guess I could've saved myself all this typing and just said "buy them all"