Through the examination of the experiences of a pre-service teacher participating in a field-based science methods course, we make evident the ways in which a combination of collaborative teaching experiences and reflexive dialogues allowed for the evolution and transformation of her identity. This teacher is Johaira Lara, the second author of this paper, and we have engaged in a cowriting approach that has created layers of writings over time, with the focus of providing evidence of her changing perceptions and understandings of teaching and learning science. We describe the ways coteaching and cogenerative dialogues provided the opportunity for Johaira to examine and reconsider her views on science teaching, and mediated the production and transformation of her identity. We offer an evolving analysis of her identity transformation related to specific aspects of the course that were pivotal for her emergence as an elementary teacher of science.