Teachers can play critical roles in challenging or reinscribing dominant narratives about what counts as STEM, who is seen within STEM disciplines, and how these disciplines should be taught. However, teachers have often experienced STEM in limited ways in their own education and are thereby provided with few resources for re-imagining these disciplines. While teacher educators have designed learning environments that engage teachers in new forms of disciplinary activities, there have been few accounts that describe how teachers make connections between these experiences and dominant narratives that impact their own and their students' learning. In this study, I report on the experiences of Alma, a white, working-class, female elementary teacher in an online graduate certificate program for K-12 engineering educators. Through her engagement in engineering design in the program, Alma appropriated--transformed and made her own--discourse of the engineering design process in ways that trouble some of the narratives that restrict her, her family, and her students in STEM and in school. Alma's experiences emphasize the need to consider not just what teachers learn about disciplinary tools and discourses, but how they transform these for their own purposes and contexts.