When an endangered or minority language is spoken by children and taught in schools, both oral and literacy skills are crucial for continued language maintenance. In school settings, literacy skills are often prioritised to support the transition to second language literacy, and rich oral language development is overlooked. This paper presents a transdisciplinary collaboration between a language researcher, curriculum support staff and educators in Warlpiri schools, designed to address this. In the project, language documentation research was re-purposed to support professional learning for oral first language development. Educators increased their metalinguistic knowledge and understandings of children's oral language development. They planned programs to meet the learning needs identified from children's data and mapped these to curriculum documents. They enhanced their capacity to develop the Warlpiri language skills of their students and promote children's bilingual, and potentially biliterate, language development. The process and practice described are transferable to other minority, Indigenous and endangered language teaching and learning contexts.