Who is London Lane from Forgotten and what is their importance?

London Lane is the sixteen-year-old protagonist of the book. She lives with her mother in the town that her mother grew up in. London doesn't know her father and isn't aware that she used to have a brother. London is unable to remember either the distant or recent past. She is however able to "remember" things from her near and distant future. London spends the first part of the book trying to remember things about her day-to-day life.