Women are well-represented in faculty development leadership positions, yet there are inconsistent support systems in place for women leaders. Faculty development requires a unique leadership skill set to work with stakeholders across the institution. We conducted a collaborative self-study to investigate how co-mentorship provides women faculty developers a space to explore and develop leadership identity and practice. Data included teaching philosophies, journals, and transcribed co-mentoring meetings. Using grounded theory, three themes emerged: proficiency, self-efficacy, and advocacy. Considering the interplay between the themes, we conceived the Faculty Development Leadership Co-Mentoring Model as a promising approach for supporting women leaders.