I'm looking for a book I read ages ago. I don't remember the title or author but I remember the cover.
It featured a sad girl hugging her knees to her chest in the sand next to a lake. There's a little twig sculpture in the sand next to her. In the distance is a large figure. The cover was primarily blue.
From what I remember, the story was about a lonely girl who uses magic by stringing twigs together. I think she summons/befriends a giant lake creature.