This is an interesting creative writing assignment. Since the first few paragraphs of the opening chapter are set in the present--with the remaining chapters being told in a retrospective fashion many years in the past--I would make your Chapter 32 a present-day commentary, narrated by the adult Scout--tying it in with the first chapter. It wouldn't need to be very long, perhaps just a reflection of Jem's injuries and what happens immediately after the attack. Sadly, Scout already tells us that she never sees Boo again; it would be great to hear her stories about Boo after the attack. You may want to include some imaginary near-sightings of Boo, or perhaps a story about what happens to him. Does he remain inside the Radley house forever, or does he eventually leave and attempt to live a life of his own in another town? Does he die, and does he have a small funeral attended by only a few neighbors like the Finches and Miss Maudie? Do more gifts mysteriously appear from him once again? This would also give you a chance to explore Scout's (and/or Jem's) teen years or her leaving Maycomb and going off to college; you may even want to mention events that happen to Atticus or even Mayella. In any case, try and connect this final chapter with the first page of the novel. It would be a perfect opportunity for you to answer some questions about the characters that may have been puzzling you.