And now we know! Deadline says she's officially cast as Fantine, who is totally one of the 99%. She works in a factory and is totally a good girl, but gets fired because a horrible supervisor learns she has a child out of wedlock. Fantine ends up on the streets, sells her beautiful hair and soon becomes a prostitute. Then she dies.
This is just like the first act! See, she worked at the factory owned by Jean Valjean, a fugitive who has become rich (to be played in the film by Hugh Jackman). When Jean, a very good guy, learns about Fantine's fate he vows to take care of her daughter Cosette.
Fantine doesn't really have any of the best songs, in my opinion. Ironically THE best song is the one Hathaway sang at the Oscars, which goes to a secondary character, Eponine. Les Mis is sort of a weird show like that. Fantine does have a great solo, though, and this is that song, which you will surely hear Hathaway belt out: