Emily
Yes, this young lady definitely knows her stuff. And over 400 pages is quite an accomplishment to write about just 1 deck.
I also have the bigger companion book, I read somewhere that due to publishing restrictions on how much she could write, she couldn't fit all she wanted to in the book that comes with the deck so she wrote the bigger companion - in the smaller book the Wand Ace has one page but in the bigger book, it has four, as most of the other cards do. She also goes into detail explaining the images on the cards. It is one of the best companion books I've read in a long, long while. Well worth getting.