It's "ok"
I just finished Age of Miracles and I would say that it is interesting enough to give it a read. The premise of the novel is that all of a sudden, the earth's rotation suddenly begins to slow. As the days and nights get longer, the narrator--a sixth grade girl--struggles with all the usual sixth grade issues in addition to a world that is slowly falling apart. I picked up this book because it is ostensibly science fiction, but its problem is that it's not quite sure what it wants to be and the result is that it just kind of sits in limbo. This really ought to be classified as a young adult book, yet there is some strong language (not that young adults don't use strong language). It also wants to be a science fiction novel, but the core premise--the slowing of the earth--is unexplained and not based on physics, however its effects are. That breaks the cardinal rule of science fiction, nudging this story into fantasy territory. Finally, Walker, at times, writes with a sophomoric flourish that seems to indicate that she wants this book to be literary. There are several stand-out passages, but ultimately, if you want to read this book, it will hold your attention, it just won't blow you away.