This book was cute, and an easy read. And it was about leprechauns, which is unique.
However, it was also a little simplistic (I guess it makes sense because of the middle-reader age group), and the characters were mostly flat, under-realized. It wasn't bad, but it wasn't amazing.
In Green, Lilybet Green discovers a mysterious package on her doorstep on her 13th birthday. She opens it, and out explodes a few leprechauns. They explain (sort of) that she is to face her trials in order to become the next Keeper of the gold from the Green clan. She must pass three tests to earn this new job, and to ever be able to go home again.