Despite the focus on motherhood and sport participation in recent years, the motherhood and recreational sport participation nexus is not well understood. Using an instrumental case study, we explored running facilitators for competitive recreational mother runners to advance research using a novel theory (i.e., narrative inquiry). We used a dialogical narrative analysis to identify a key theme of “good mother runners: negotiating freedom and constraint.” Findings are presented using a storyteller approach in the form of three portrait characters who each tell a story of facilitators grounded in a “relational narrative” that provided freedom to run in the context of good motherhood. The features of the relational narrative are shown in three nonfiction vignettes: Susan’s story, “Running is what we do”; Tracy’s story, “Running isn’t just for me, it’s for them”; and Kay’s story, “Just go with it.” Interpretive reflections of the stories using narrative theory are offered. We conclude with practical recommendations and future research directions for mothers’ competitive running participation.