LightMasters: Number 13 by M.G. Wells

Orphaned after her parents' tragic death, Jessica Wyrd feels uneasy living with her gassy grandparents. With few friends and constant teasing by her hardcore schoolmates, this Georgia girl feels like an outcast living in a small town in upstate New York.
Anxious about being forgotten on her 13th birthday, Jessica is lured into the forest by a strange spiral light. She encounters three Lighmasters, who convince her that she has unique gifts. Intrigued, she's transported to another dimension where she is tested for her courage and strength.  Things change drastically when Jessica returns to earth. During school, her reality shifts and people start turning into reptilian monsters.

The leader of the Lightmasters tells her she's needed by the alliance to defeat an invisible alien beast, who feeds off fear. How can Jessica conquer her own fears and help rid the world of a wicked enemy who hates humans? From Goodreads

This book wasn't quite as gripping as I had hoped. It was interesting enough and it was rather fast paced but I just didn't get caught up in the book. I liked the grandparents of the main character Jessica more than her.

I read this book as part of the Winter's Respite Read-a-Thon.hosted by Michelle at The True Book Addict.
It also qualifies for: 
100 books in a year Reading Challenge 2012, 
Goodreads 2012 Reading Challenge, 
2012 Ebook Challenge, 
Why Buy the Cow? Reading challenge 2012 ( the book was free on Amazon.com on the 12th of January 2012)