Hallucinations, fate or some sort of mania brought on by her brain tumor, she wasn't going to wait for the Grand Canyon.
Such hallucinations are commonly provoked by crystal-gazing, but auditory hallucinations may be caused by the use of a shell (shell-hearing), and the other senses are occasionally affected.
From an evidential point of view the apparition is the most valuable class of death-warning, inasmuch as recognition is more difficult in the case of an auditory hallucination, even where it takes the form of spoken words; moreover, auditory hallucinations coinciding with deaths may be mere knocks, ringing of bells, &c.; tactile hallucinations are still more difficult of recognition; and the hallucinations of smell which are sometimes found as death-warnings rarely have anything to associate them specially with the dead person.
Parish, Hallucinations and Illusions and Zur Kritik des telepathischen Beweismaterials, and Mrs Sidgwick's refutation in Proc. S.P.R.
CRYSTAL - GAZING, or Scrying, the term commonly applied to the induction of visual hallucinations by concentrating the gaze on any clear deep, such as a crystal or a ball of polished rock crystal.