What is the author's style in Numbers: Book 1 by Rachel Ward?

The story is presented in first person from the limited perspective of Jem, a fifteen-year-old orphan at the time the story begins. This limitation means the reader doesn't know anything unless that information is available to Jem. For example, it's not known whether Jem's mother had the gift prior to Jem's birth. Jem's mother was a heavy drug user and it seems possible that she became caught up in the drugs as a way of escaping the onslaught of numbers indicating the dates of death for those she met. Jem says she can't imagine looking into the eyes of her child and knowing the date of that child's death, but she loses the gift by the time Adam is born.