What is the narrator point of view in the novel, Invisible Emmie?

The point-of-view of the novel is essential to its very heart. At first glance, the book seems to alternate between two separate and distinct first-person narrators: Emmie, a shy and quiet girl who loves art, and Katie, a beautiful and popular girl who everyone loves. However, when the novel concludes Emmie reveals that Katie is a cartoon character she created for her comic strip.