In the novel Fantine has been in the hospital for at least 6 weeks but it's not really specified how long. She is waiting every day for Cosette to come. Valjean keeps promising Fantine that Cosette's coming but every time Valjean sends someone to fetch Cosette the Thenardiers refuse to give her up. Valjean has decided to go get Cosette himself but was sidetracked by the Champmatheiu ordeal.
Valjean visits Fantine every afternoon, but has been gone two or three days. Fantine and the nurses are convinced he's going to get Cosette. Then suddenly Fantine hears children's voices outside her window. The nurse tells Fantine it is Cosette she hears but that the doctor won't allow Fantine to see Cosette until Fantine gets stronger. The nurse says this because she believe Valjean will be back soon with Cosette.
Valjean appears and the nurse is upset that he didn't get Cosette. Valjean goes to Fantine to check on her but suddenly Javert comes into Fantine's hospital room and spills the beans that Valjean is not the mayor, he is a convict, and that Cosette is not there and Valjean will be going to jail and not be going to get Cosette. The shock of this news causes Fantine to die.
So while the song has Fantine "imagining" she is seeing or hearing Cosette in the novel Fantine really believed she was hearing Cosette right outside her window.
Here's the section of the novel where Fantine dies.
In the novel Fantine has been in the hospital for at least 6 weeks but it's not really specified how long. She is waiting every day for Cosette to come. Valjean keeps promising Fantine that Cosette's coming but every time Valjean sends someone to fetch Cosette the Thenardiers refuse to give her up. Valjean has decided to go get Cosette himself but was sidetracked by the Champmatheiu ordeal.
Valjean visits Fantine every afternoon, but has been gone two or three days. Fantine and the nurses are convinced he's going to get Cosette. Then suddenly Fantine hears children's voices outside her window. The nurse tells Fantine it is Cosette she hears but that the doctor won't allow Fantine to see Cosette until Fantine gets stronger. The nurse says this because she believe Valjean will be back soon with Cosette.
Valjean appears and the nurse is upset that he didn't get Cosette. Valjean goes to Fantine to check on her but suddenly Javert comes into Fantine's hospital room and spills the beans that Valjean is not the mayor, he is a convict, and that Cosette is not there and Valjean will be going to jail and not be going to get Cosette. The shock of this news causes Fantine to die.
So while the song has Fantine "imagining" she is seeing or hearing Cosette in the novel Fantine really believed she was hearing Cosette right outside her window.
Here's the section of the novel where Fantine dies.
http://www.classicreader.com/book/268/69/