". . . my dear, it has been apparent that you do not have what the noble art of Divination requires. Indeed, I don't remember ever meeting a student whose mind was so hopelessly mundane."
. . .
"Fine!" . . . "I give up! I'm leaving!" And to the whole class's amazement, Hermione strode over to the trapdoor, kicked it open, and climbed down the ladder out of sight.
. . .
"Oooo, Professor Trelawney, I've just remembered! You saw her leaving, didn't you? 'Around Easter, one of our number will leave us forever!' You said it ages ago, Professor!"
Professor Trelawney gave her a dewy smile. "Yes, my dear, I did indeed know that Miss Granger would be leaving us. One hopes, however, that one might have mistaken the Signs. . . The Inner Eye can be a burden, you know . . ."
. . .
"Some day Hermione's having, eh?" Ron muttered to Harry, looking awed.
Harry potter and the prisoner of Azkaban
What does the sentence marked in bold, especially "have" mean?