This article reports on a collaborative inquiry into the use of a researcher-designed digital tool for the support of writing instruction in elementary classrooms. The digital tool in question is an online collection of original writing samples produced by elementary children that was conceptualized as a resource for coaching new writers using easily retrievable samples of "gems" produced by other young writers. This article describes the teacher education context from which the design of this tool emerged as well as the evaluation of this tool by a group of Master Reading Teacher candidates. Grounded in the literature on the use of mentor texts in writing instruction, this article highlights the role that authentic child-authored texts can play in supporting teachers' instructional moves. The article ends with a discussion of implications for enhancing teacher professional development through the use of digital tools that can be utilized to promote reflective inquiry into writing pedagogy.