This paper reports on research into the literacies of pre-service teachers and the implications for both mapping and developing students' literate competences. The research focussed on two questions: (i) If tertiary literacies are multiple, how do we bring these into relationship with one another and with the different discourse domains of professional life? (ii) What does development 'look like' in a multiliteracies environment? The research investigated the linguistic challenges of all assignments undertaken by 11 students in the first 18 months of teacher education and this paper considers how one student negotiated the challenges of three of these. Drawing on tools of register and genre within systemic functional linguistics, our paper explores the genesis of a model to encompass a wide range of assignment tasks related to academic, everyday and professional discourses of teacher education. Following this, it applies genre and register analysis to the writing produced by one student and reflects on the implications of her negotiation of these tasks. A dialogic model of development is proposed which images learning as an ability to shunt between the register demands of different domains. The student integrates sometimes competing meaning potentials through the production of a text in a particular genre. Development is construed in terms of this dialogue. The paper concludes with a discussion of the potential of the framework for both including the diverse literacies of teacher education and for exploring the kinds of learning that occurs at the intersection of (often competing) discourses.