It’s good to have an general essay, or at least essay plan, prepared for theme, character, character conflict and key scene.
You can bet on one of those essays turning up in prose, however don’t stress if you haven’t done them all, a couple you sort of know is okay for the prelim.
All I had for the Nat 5 prelim was theme!
For the actual exam though I covered theme, character conflict, strong character e.g. admirable character (something along those lines), a character who had developed over the course of the text, key scene, turning point and ending. (turning points and ending can also be key scenes, but the ending can’t rly be a turning point bc nothing happens after that).