The Ice Children by M.G. Leonard
 
At the stroke of midnight on the dawn of December, five-year-old Finn Albedo is found frozen in the city park on a pedestal of ice. Finn's big sister, Bianca, suspects that the beautiful sparkling book Finn got from the library has something to do with it, but the book has vanished. Each day, more children are found frozen and Bianca realizes she's running out of time.

Her quest to discover the truth and rescue her little brother hurls her into a fantastical winter wonderland, full of beauty, danger and irresistible spirit animals, where all is not as it seems. Can Bianca save her brother and the other Ice Children before they are forever lost?