Thunder storms up the bestseller lists

Flags are out in three countries, celebrating the last of the World Wise Writer gals to release her debut novel. Only been out a couple of days and it already hit #26 in the Amazon US Bestsellers list for Children's Sword & Sorcery Fantasy Books. That's against stiff competition like Harry Potter, Percy Jackson and The Hobbit.
Here's the deal:

When fifteen-year-old Olivia Williams and her two younger brothers wake up from a car crash, they’re positive their world has changed. The talking horse is a big clue. And he has a lot to say. According to Thunder, fairies, magic and good ol’ St Nick are all for real. On some level. Which would be incredibly awesome, but there’s a problem. A rift has formed between the layers of existence, and the evil Sliders are taking advantage of it—bringing violence, fear and hatred with them.

Now the three siblings are immersed in a tangle of reality and fantasy. One with trolls, freakish amphibians ... and town-devouring rats. Fortunately, help is on hand as Thunder introduces them to a world of Shifters and other powerful beings. Like Olivia’s very own Guardian, Ethan. Whom she actually does like. A lot. How could she not, when his job is to stand between her and death?

With humanity at stake, the Williams children must do more than accept the unbelievable. They must accomplish the impossible. The rift needs to be sealed and they’re the only people alive with the potential to do it.

You can buy it now on Amazon US or Amazon UK - at a mere $3.99/£2.43, it's one of the biggest bargains you'll find today. See what other people have said about it (follow the link for your country's Amazon and click on comments) and if you are still not convinced, read an excerpt on her blog.
When you've enjoyed meeting Olivia and her brothers, a comment would be awesome.