A Participatory Design Research (PDR) conducted with fifteen Chicana dual language bilingual teachers in New Mexico focused on expanding their understandings of their own translanguaging, so as to transform their concept of biliteracy and design their biliteracy instruction as a site for resistance and transformation of bilingual marginalized students. After reviewing how translanguaging shapes understandings of biliteracy, and describing the intervention done with the teachers, one teacher's emerging transformative stance toward biliteracy is highlighted, as she co-designs a borderland biliteracy unit within her Spanish Language Arts curriculum. The article shows how this teacher's instructional design impacts the students' biliterate learning by highlighting the work and writing of one student.