As far as the content of this mysterious "book" she's reading, it could very well come true, it also might not.
If it was me, I would tell her not to worry, and that someday, each and every one of us will die,(most likely) however sooner or later all depends on fate, and that no matter what, we'll all make it through somehow. I wouldn't worry about it, maybe just take note of it, and then get on with life, and see what happens next.
We're not looking to get her a prescription, that's why we're taking her to a psychologist (psychiatrists prescribe medication, psychologists are like counsellors and analyse if there isn't an underlying problem, like nightmares due to stress over exams or something along those lines). Dad just wants to find out if there is any other explanations for her behaviour.