DD2(10) is doing Piggy Princess, from the play Flowers in the Desert. (This can be found online)
DD1(12) also did the scene from Secret Garden, where Mary tells Colin off. This year she is doing a scene from the beginning of Vanity Fair, where Becky and Amelia are travelling to Amelia's house, after leaving the school.
Anne Fine's "Diary or a Killer Cat" is hilarious, and the story is told by the cat, with parents and children as 'supporting actors'. There is a 'death scene', so if you select the right bits it can cover everything: