Tanglewreck by Jeanette Winterson 414 p.

When Time Tornadoes start to disrupt life in England, eleven-year-old Silver Rivers is somehow involved, although she knows not how. Her parents and sister have disappeared, her miserly aunt takes poor care of her, and an evil alchemist is convinced that Silver must have the missing Timekeeper last seen in her father's possession. Without this clock, Time will rip apart. With help from Gabriel, a friend from below-ground London, Silver must save the world.