This article focuses on the experiences of transnational Latinx youth and families through historias shared by the mothers. Transnational communities such as those from Latinx immigrant backgrounds have acquired critical perspectives because of their experiences in and across borders that have become central to their understanding of how to navigate learning in the U.S. context. As such, learning about border-crossing knowledge and literacies from transnational students, families, and communities has become increasingly relevant and a timely pressing topic in today's U.S. language and literacy education and beyond. This study employed a pláticas methodology to capture how transnational Latinx mothers storied their bilingual children's biliteracies. This study draws on transnational literacies and transcultural knowledge to conceptualize border-crossing biliteracies, a lens for understanding how transnational children read and write the world. Drawing on this lens, the findings reveal how transnational Latinx families disrupt and expand the meaning of family, language, literacy, and cultural teaching and learning for transnational Latinx youth. Rooted in their experiences, this article discusses and unpacks the meaning of border-crossing biliteracies pedagogy and offers implications for bilingual educators, curriculum developers, and researchers.