This article proposes ways to authentically amplify writer's workshop for emergent bilinguals. Through the study of one bilingual teacher's mediation in teaching, we examined the affordances that translanguaging and transmodal practices have for emergent bilingual students' writing processes. In this case study, we focused on a writing sequence associated with the well-known Latin American holiday of the Day of the Dead, in which 3rd grade emergent bilinguals wrote "calaveras," or literary poems, as part of an interdisciplinary language arts and social studies lesson. Our work is framed by sociocultural theories of mediation, literacy, and language. Under a multiliteracies pedagogy, we observed how a bilingual teacher and emergent bilinguals negotiate meaning through a variety of linguistic and multimodal resources. In our interactional analysis of talk, we found how the teacher mediated background knowledge and vocabulary as a part of the writing process; we also identified ways in which her mediation included extensive scaffolding as she provided linguistic and disciplinary knowledge needed to write calaveras. Through integrating the tenets of mediation with biliteracy, multiliteracies, and translanguaging pedagogies, this study offers a promising example of how teachers can build a culturally-sustaining writers' workshop to support emergent bilingual learners' language development and writing practices.