Emlyn's Moon by Jenny Nimmo

"Nia can't do nothing!" is the taunt Nia Lloyd hears from her brothers. The middle child of a family of seven, she feels lost in the shuffle until she befriends Emlyn Llewelyn. But her parents don't want her to go to the Llewelyn home. "Something happened there" is all her brother will say. But Emlyn's cousin Gwyn is a magician with a magic snow spider when it spins a web for Emlyn to glimpse another world, danger threatens. By helping Gwyn and Emlyn, Nia finds a way to do something important. (Emlyn's Moon by Jenny Nimo. The Magician's Trilogy: Book Two. Read by John Keating. Scholastic Audiobooks, 2006.)