Like many others, I picked this book up on a whim too, and I've got to say, I'm very satisfied with it. It is exactly what I expected- a classic style fantasy, with goddesses and magic and creatures aplenty, maybe even more than the comparatively diminutive length would warrant, and an ending that, twenty pages before it, had me wondering how on Earth it would have enough time to wrap itself up properly. (And to answer that, it kinda didn't, but it also kinda did? Definitely difficult to define.)
Up front, the best way I can describe it is that this book is kind to its reader, if it is the right person holding it.
It doesn't over-explain things, if you've read your fair share of fantasy novels already: it builds upon what you already know, weaving the classic and the refreshing into such an intricate knot, the end result is both already done and sweetly new, a quintessential fantasy (that, I would argue, echoes more of a feminist viewpoint than one might expect from the genre's contemporaries). It takes you on a ride, but not one that will have you on the edge of your seat- rather one that will have you settle comfortably into your favorite chair, and be entertained for a nice handful of hours.
Crystal, the protagonist, is your bona-fide wizardess, and what I like to call the Little Girl Power Fantasy: she is gorgeous beyond compare, a kind and gentle beauty whose song cures the dying and soothes the living, yet she is stronger and more capable than every single man in all the lands who in turn, fall head over heels for her. Her clothes are woven from snow and woodsmoke, her eyes so mesmerizing that the very concept of death falls in love with her, and she is so strong that she can make mountains crumble with her scorn and routinely bail her love interest out of trouble with her Awesome Muscles. She is perfect, but not in a way that is boring or annoying- which is thanks in part to her softness, and the charmingly beautiful storytelling interlaced with subtle, playful humor.
The two books, Child of the Grove and The Last Wizard, have precious little to do with each other beyond that they share her as a protagonist, set a dozen years apart. (In fact, I would say that Child of the Grove only half has her, given that she's born a generous hundred pages into the book, but never mind such technicalities.) They are very different books, unified only by the style of prose and a handful of characters, but let's be real... if you enjoy the genre enough to find this book and pick it up, chances are, you've read series with less in common between its installments, and you're going to have a nice, not overly demanding or serious time with it. Give it a try.