Hi, Elizabeth —
Doing some Googling, I see some definite red flags about this book. For examle, supposedly, the visionary described by the book can tell you the destiny of your dead loved ones — this is a red flag. From what I understand, this woman's visions were never approved, as they should be by the local bishop.
In general, it is wise to be careful about claims from so-called visionaries and mystics.
As it turns out, we already answered this question. See:
Hope this helps,