Okay, so the big twist in 'Push'? You've got to separate the book from the movie. In Sapphire's novel, the central shock isn't just the abuse Precious endures. It's the structural reveal of how deep the betrayal goes, told through her own fractured writing.
The story is presented as Precious's journals for her literacy class. The early entries are these raw, phonetic blocks of text – you're inside her head, feeling her confusion and pain. The twist unfolds as her writing itself transforms. She starts to articulate, clearly and horrifically, that her father, Carl, is not only the father of her first child, Little Mongo, but also of her second child, Abdul. Her mother has known all along and actively enabled the abuse, even blaming Precious.
It's less a single 'aha!' moment and more a dawning, awful clarity for the reader that matches Precious's own. The real pivot is witnessing her consciousness awaken through language. The abuse was the known horror; the twist is seeing her claim her own narrative, piece by painful piece, and realizing her mother's complicity was the final lock on her prison. The journal format makes you experience her isolation directly, and the plot 'twist' is really the plot becoming coherent to her for the first time. The monster had a face she always knew; the new horror was naming it fully.