The reviewer here, Peirce Oka of the delightfully named Dogma & Dragons,  had the good taste to like my wife’s book:

The Unexpected Enlightenment of Rachel Griffin is not a book to be read at funerals. Within the first chapter or two you will begin cracking up, holding back tears of laughter, and all your relatives will turn to look and see you reading a YA novel when you should be paying attention to the moving eulogy on your Great Uncle Stanley’s love affairs with golf and sharkboxing, the latter of which got us all here in the first place, but at least he died doing what he loved. They will then proceed to passively-aggressively deny you the best desserts at the funeral reception. For similar reasons, you should avoid reading this book at weddings, baptisms, confirmations, bar mitzvahs, ordinations, inauguration ceremonies, and circumcisions.

The aforementioned cracking up will be chiefly creditable to one Siegfried Smith, dragonslayer and destined to be a fan favorite. A few other characters bring some mirth to the proceedings, such as Valerie Foxx, plucky girl reporter, and her dog, Payback; and Nastasia Romanov, Princess of Magical Australia, but by and large Siggy carries the comic weight of the work, like Atlas hefting a magnificent globe of silly putty with googly eyes stuck all over it. Thankfully, authoress L. Jagi Lamplighter delivers Siegfriend in just the right doses to her readers to keep them laughing throughout the story but without overwhelming the main narrative and its heroine, the eponymous Rachel Griffin.

Myself, I think the review would have been better if it had spoken more about those wonderful, wonderful illustrations.