There is exactly one moment of narration after the intro - in the library with Bella, when he says:
That's it. That is, so far, the only narration post-introduction. The fact it is the only time DPC has done it makes it
IMPORTANT. It could be something other than her dying, but the major event of the story's climax (not that kind of climax!!! I'd tell you to get your mind out of the gutter, but I'm on this site too...) is going to involve Bella's very bad awful terrible day. You can't draw that much attention to a (metaphorical) gun in the first act if you aren't going to use it in the fifth act.
My guess; she is going to sleep with the MC, and feel so guilty she kills herself. Or she gets over her reservations, sleeps with him, and then her husband walks in on them and storms off again. She might get so jealous she goes on a kill crazy rampage, or something else entirely. But it will be a bad day for Bella.