Objective To evaluate the psychometric properties of the Parental Education in Physiotherapy (PEP) scale, designed to assess the extent to which pediatric physiotherapists implement family-centered educational practices and caregiver education strategies for families of children under 6 years of age. Methods This is an instrumental cross-sectional study based on a digital survey targeting physiotherapists in Spain. A sequential cross-validation procedure was applied by randomly dividing the total sample (N = 310) to two equivalent subsamples (n = 155/155). The final 8-item set was selected in Subsample 1 based exclusively on the EFA results and theoretical considerations, before the CFA results were examined. The prespecified 8-item, 3-factor structure was subsequently evaluated through CFA in Subsample 2. The CFA was estimated using diagonally weighted least squares (DWLS). Convergent validity evidence was examined using average variance extracted (AVE), and discriminant validity evidence was examined using inter-factor correlations, while associations with the use of technological devices for motor tracking were analyzed as an exploratory external comparison. Internal consistency was estimated using reliability coefficients appropriate for ordinal data. Results A total of 310 physiotherapists participated (mean age = 36.4 years; 87.4% women). The final 8-item, 3-factor model (Collaboration, Capacity-Building, and Reflection) showed excellent fit (CFI = 1.000, RMSEA = 0.011, SRMR = 0.031), AVE values above 0.50 in all three factors (0.587–0.771), and latent factor correlations below 0.85 (0.40–0.64). Internal consistency was adequate for the three subscale scores. Reliability coefficients for the total composite score were also reported descriptively, although a global factor was not evaluated. Conclusion The PEP is a brief measure with promising initial psychometric properties for describing and reflecting on family-centered educational practices and caregiver education in pediatric physiotherapy. Its three-dimensional structure and digital format may facilitate professional reflection, training, and quality- improvement initiatives within family-centered care models.