Intimations of the PE
If normal life is the start, you author (and reader) probably wants this normal life to be interesting reading. One technique for adding interest is the intimation of things to come.
As noted, The Princess Diaries has chapters of the main character's normal life before getting to the PE. Of course, Cabot tries to make that interesting. But there are limits -- no one buys this book to read about the main character's normal life.
Cabot provides intimations of the PE. On page 10 (trade), her dad calls wanting to speak to her mother. Page 15 he calls again:
He sounded all weird on the phone again, so finally I was like, "Dad, is Grandmere dead?" and he got all startled and said, "No, Mia, why would you think that?"
And I told him it was because he sounded so weird, and he was all, "I don't sound weird," which was a lie...
Providing one or more intimations seems to be a normal technique for when the PE is delayed for a while.
The easiest way to intimate is simply to tell the reader that something's coming.
I think that's wrong. Maybe you don't mind the narrator talking about the future, but it takes me out of the book. (And it suggests to me a lack of writing talent.)
Ironically, if your intimation is too obvious, the reader might wonder why the character doesn't see it. If it's too subtle, the reader might not see it. One solution is to make the intimation slightly out of place in the flow of the story. Cabot's first intimation:
I was measuring my chest and totally not thinking about the fact that my mom was out with my Algebra teacher when my dad called. I don't know why, but I lied and told him Mom was at her studio.
Cabot smoothly weaves that into the timeline, as she should, but it has nothing to do with the actual underlying story.
The underlying idea is that a good writer usually provides only the information needed to create a good scene. The presence of extraneous information could just mean that the writer is not skilled in that (or not inclined), but out-of-place information usually means the information will be later meaningful.