The Developmental Model of Sport Participation (DMSP) describes trajectories young athletes commonly follow in their sport participation, involving sampling, specializing, investing, and recreational phases of development (Côté & Fraser-Thomas, 2011). Several physical and psychosocial factors characterize each trajectory (e.g., types of activities, influences of families, coaches, and peers), in turn leading to differing performance, health, enjoyment, and psychosocial development outcomes. While the DMSP has been widely used as a framework to understand youths’ sport development (e.g., McCarthy & Jones, 2007), few studies have explored the interactions among the DMSP’s key factors over time using a holistic framework. The purpose of this longitudinal case study was to examine the sport development of a young athlete throughout the sampling years of the DMSP. Participants included the female child-athlete, her father, mother, and coach. Semi-structured interviews were conducted with participants at yearly intervals, from the time the child was aged seven to ten. In addition, practices and competitions were observed, and the child’s mother completed demographic and sport history questionnaires. Findings offer a comprehensive understanding of the child’s sport development experiences through the lens of key stakeholders, with themes relating to key factors within the DMSP. For example, given the child’s involvement in numerous sporting activities, parents were conflicted between promoting sport diversification or specialization. As the child worked with several coaches over the course of the study, findings shed light on her adaptation – or lack thereof - to different coaching philosophies. Further, the child was a top performer, regularly training/practicing with older athletes, yet her sport enjoyment was inconsistent throughout these experiences. This case study captures some of the nuances of children’s early sport experiences and enhances understanding of how young athletes eventually achieve performance, health, and psychosocial outcomes. Key areas for future research are discussed.