The article presents a classroom‐based study that engaged linguistically diverse preschool and early school‐age children in illustrating books, jointly composing written narratives to accompany their illustrations, and enacting these child‐authored books through shared sociodramatic play. Findings from story retell tasks show significant improvement in children's narrative language: vocabulary, syntax, accuracy, and text structure. Analysis of collaborative dialogue during book‐making highlights the role of peer and teacher scaffolding in supporting children's literate language and identity development. The article presents an engaging play‐based approach for ECE educators to (1) significantly and equitably increase child‐led literate language interactions; (2) improve early writing instruction, by increasing meaningful composing experience; (3) strengthen culturally sustaining home/community–school partnerships, through authentic dialogue with caregivers about children's writing; and (4) harness the social and multimodal power of play to promote a range of important early learning goals.