This article focuses on the methodological use of reflective narratives from discourses and activities of an experienced primary teacher as evidence of her professional identity. The teacher's reflective narratives emerge from her participation in a 3-year developmental and research project, Learning Communities in Mathematics, conducted at the University of Agder (UiA) in Norway. As background for our study, we firstly present the teacher in action with her sixth-grade pupils in a mathematics lesson, and then analyse selected clusters of reflective narratives from different empirical situations in the project. We have identified four identity indicators, which have been elaborated and organised thematically, related to the teacher's engagement and critical alignment in the community of participants: (1) Positioning in relation to pupils, (2) Reflecting on developing a workshop model in teaching, (3) Integrating and expanding models of teaching and (4) Challenging positioning in relation to didacticians. These indicators provide evidence of the teacher's professional identity. We suggest that the emergence of these indicators also gives empirical evidence of professional teacher identity development.