In youth women’s tennis, building a performance model requires linking physical traits and motor capacities to competitive progression without harming long-term development. Here, sustainability means guiding training and talent pathways through evidence-based, age-appropriate, and individually tailored criteria, limiting early-specialization bias and weak selection practices. This pilot study explores the anthropometric profile and selected motor indicators of U18 female tennis players to outline preliminary reference trends for a sustainable youth performance framework. An experimental field-based design was used, assessing basic anthropometrics (e.g., height, body mass) and tennis-related motor capacities through a sport-specific test battery. This work represents a first step toward an optimal youth performance model that supports talent identification and long-term athlete development using measurable, context-sensitive parameters. Results may help coaches align performance improvement with sustainable growth.