This study offers ways to understand how a fifth-grade student and her teacher co-constructed academic and social positions within classroom writing practices and how these positions constrained and enabled literacy learning. Positioning is viewed as central rather than optional to learning. Classroom writing practices enabled the case-study participant of this study, Lucy, to explore the possibilities of who she was as she determined what types of learning were socially available to her. For 9 months, the teacher researcher collected and analyzed data from her students. Students' writing samples and conversations around their writing were used as primary evidence. This article represents a case study of Lucy, who was determined to have used positional writing practices to position herself as she constructed identities. Results indicate that Lucy held meanings for certain positions. These meanings influenced her participation or lack thereof in various socially and culturally constructed communities and influenced her learning. Lucy engaged in positional writing practices to create spaces or possibilities for herself to influence and to examine her and others' positions. She attempted to connect, distinguish, protect, and enhance herself through writing practices. As Lucy's ways of using positional writing throughout the school year shifted, she explored opportunities for using writing in creative, academic, and personal ways. Lucy's case study provides insight for educators and researchers interested in learning about how relational identities influence students' literacy learning.