What a wonderful idea! If we were going to create a memory box for Miss Maudie, we'd want to include the things that reminded us the most of her. That would mean something related to her great cakes (a plate? a fork?), something related to her beloved yard (dead weeds?), something to remind us of her wonderful stories, especially about the Bible, and something to remind us of her house that burned down (a pinch of ashes, most likely). If we wanted to make it more inclusive, we might include something related to the stories she shared about Atticus (Ol' One Shot!).
That's a very interesting and creative idea. If you want to create a memory box for Miss Maudie Atkinson, you could place memories and objects that symbolizes her personality and her character and what makes her memorable in the entire story.
Maybe, you could put memories and thoughts about her burnt house, how she still become strong and steadfast after her loss of his only home and protection, or maybe the slice of the adult cake that she gave to Jem, an acceptance for his "coming-of-age". You could add collections to her memorable stories that she tell to the children, including the foot-washing baptist or maybe add to the collection her beautiful yard, the flowers that she had grown herself. You also could add to the scene when she defended Atticus at the Missionary Tea.