Of course it wasn't her mother's voice she heard. It was mine. Because the dead never sleep, you see. We have so many other things to do.”
-- Pearl (“The Sleep of the Dead”)

Importance: This is the first time Pearl reveals that she is a ghost, though the reader at this point does not know if this is literal or some sort of metaphor. Pearl is dead, and she does have lots of things to do by this time because she is self-aware and has remembered who wronged her in life. The reader has to keep in mind that this opening chapter is out of chronological order, and actually takes place last among the events of this novel.

Hell is never what you think it's going to be.”
-- Pearl (“Our Lady of Perpetual Sorrow”)

Importance: Pearl has just described a ghost girl at the orphanage who throws herself from a window, screaming “No, please, wait! the whole way down.” This is the first time...