Cinder is written from a third-person point of view, and there's a good reason for this. The story is a retelling of the tale of Cinderella, which like all fairy-tales, was told from the third-person point of view. A fairy-tale might start with a line like "Once upon a time, there was a princess..." Here the narrator is referring to someone, i.e. the princess, in the third person, so straight away the perspective of the story has been established.
As Marissa Meyer wants to provide us with lots of detail about the dystopian world in which Cinder lives, it's important for her to give us the broadest possible picture. This is where the third-person point of view comes in. It allows the reader to look down at the society and the people in it from a kind of God's-eye perspective. We are not part of this futuristic society, and we are not familiar with it, but we do need to understand it. So the third-person viewpoint enables us to see how everything works in this strange society and how it all fits together.