In June 2019, the Vatican published its first-ever document on gender theory. This document was directed at Catholic educational institutions and draws on theology and philosophy, while excluding science on gender identity and testimonies from transgender people, to suggest gender theory is an ideology endangering the family. The case of Jane, a practicing Catholic and teacher-leader in a Catholic secondary school, contributing to cross-disciplinary curriculum development, school accreditation, and student mentorship, is used to anticipate problems of practice which may emerge as this document's guidance is applied at the school level. Ecological systems theory and communities of practice theory are used to analyze this case.