This 2004 ethnographic inquiry, set in the evolving Winfield-Wessex context of French colonization in Ontario, interrogated the informal and formal pedagogical practices of mother tongue biliteracy in "français langue maternelle" and English as constructed through changing language policies, language ideologies, and inherited "f/Francophone" illiteracy. I focused my case study on examining the embodied interactions and effects of these practices on the study's participants within the two grade 9 languages/literacies classrooms and everyday school life at l'Envol, the French-language secondary school. I define mother tongue literacy development and related pedagogical practices as ideological concepts that contain underlying views of language, literacy, identity, and power relationships. To attend to participants' language/literacy interactions and practices, to understand them, explain their sources, how they work and their effects, I adopt an experiential framework based on my reflections and insights as a Franco-Ontarian researcher that is couched within an interpretive and critical approach to the ethnography of communication and d/Discourse analysis. My study took account of the perceptions and practices of differently positioned adolescent students, teachers, parents, members of the secondary school staff, and school board administrators all of whom reflected multiple individual, family, and community interests. By using selected excerpts from my interviews, my observations, and relevant documents that reveal a disjuncture between language ideology, pedagogy, and situated practice, I argue that the pedagogical practices of French mother tongue (in its restricted meaning and its "français langue maternelle" school literacy incarnation) create constraints and tensions for the diverse participants in Room 101 and the educational community at l'Envol as a whole. These restrictive practices invalidate students' other mother tongue identities and act against incorporating student background experience and knowledge as scaffolds for their biliteracy development. I invoke the concept of third space to bring together the divisive ideological language views and pedagogical practices of the dominant "français" space of mother tongue biliteracy and those of the English mother tongue space to build students' unified bi/multilingual repertoires as they evolve in the in-between spaces of a globalized world.