Mikhail Bakhtin's notion of appropriation is a potentially powerful way to conceptualize discourse development in children. Typically, studies of discourse development have emphasized structural aspects of text. However, children appropriate not only forms, but also words, themes, purposes, and styles. From a developmental point of view, the concept of appropriation raises at least three questions: What is it that children appropriate? Where do they get their material? And what do they do with that material? In an attempt to make sense of appropriation as a developmental construct, we examine one third-grader's writing: Suzanne's book, The missing piece. We find that Suzanne appropriated material from two major sources: (a) adult-authored text - Margaret Sidney's novel, Five little Peppers and how they grew - and (b) the meanings and values of a stratified local peer culture. We conclude by discussing the significance of this work for future research on children's discourse development. (Discourse development, Mikhail Bakhtin, peer culture, social context of writing, children's writing, appropriation).