Authentic Chinese Cuisine by Bryanna Clark Grogan!
Hmm. The reviews for this one mention a lot of mock meats. Are most of them seitan or other wheat-based things?
Well, authentic vegetarian Buddhist-style cuisine relies on fake meat a lot, so yes, this book has a lot of seitan recipes. There is a ton of other stuff too: stir-frys, vegetable recipes, dim sum using stuff like yuba and rice paper, dumplings, soups. It's pretty exhaustive. Is she comfortable with vegan cooking? If it's new to her, this book might be a bit on the challenging side.
I have a book I quite like called Buddhist Peace Recipes by Pushpesh Pant. It pulls from different cultures but has quite a bit of Chinese stuff, and is quite lovely since it is full colour and has a picture for each recipe.
I like The Asian Vegan Kitchen too, but the Chinese section is kind of small, if that's specifically what your mom is looking for.