In the book, it's impossible to act on information from the future, whereas in the film that clearly happens in the phone call near the end.
This means that if the daughter had died in a climbing accident in the film, the mother would have to have chosen to let that happen/not warn her, whereas to avoid the disease, the only option would have been not to have the child. In the book, that wasn't an option; learning the language changed her subjective experience of time, but did not give a superpower.
This means that if the daughter had died in a climbing accident in the film, the mother would have to have chosen to let that happen/not warn her, whereas to avoid the disease, the only option would have been not to have the child. In the book, that wasn't an option; learning the language changed her subjective experience of time, but did not give a superpower.