Emerging bilingual learners' biliteracy abilities are often underestimated when monolingual reading assessments, such as the DIBELS, are used to identify students as having difficulties in learning or to guide literacy instruction. The authors propose a holistic form of biliterate assessment that uses writing as a means to understand what emerging bilingual learners actually know about literacy. In this qualitative study, the authors raise serious concerns about using DIBELS and question its adequacy for measuring literacy skills for students in the early and intermediate stages of English-language development, as well as its limitations in providing relevant information about students' biliteracy. Through qualitative analysis of three sets of writing samples collected from 29 second-grade students, the authors illustrate the biliteracy skills and abilities that these students possessed holistically across Spanish and English. The students selected for this study were identified by DIBELS scores as reading below or well-below benchmark. However, through the qualitative analysis of their writing, the authors were able to document the students' literacy understandings across languages in their second-grade year through the organization of their written texts, change in sentence constructions, and alphabetic skills knowledge. This work is significant to the field of bilingual and biliteracy instruction in that biliterate writing assessment provides a means to understanding developing reading skills that is broader in scope and is appropriate for assessing the totality of emerging bilingual learners' biliteracy development.