Family involvement is a key component of educational quality, particularly in Early Childhood Education and Care (ECEC). It strengthens home–school relationships, supports children’s well-being and learning, and lays the foundation for subsequent academic success. However, most quality assessment frameworks mainly focus on structural or process-related setting characteristics, while giving limited consideration to family involvement. This study addresses this gap through the development and implementation of a complementary instrument —the Family Involvement in Early Childhood Education Module (FIECE-M)— designed to be used alongside the ITERS-3 and ECERS-3 scales. A quantitative and cross-sectional design was employed, with data collected from 28 ECEC rooms, from 13 centres in Spain, involving 42 educators and 302 children. Results reveal overall good quality and moderate-to-high family involvement levels. Significant differences emerged according to centre size, educational cycle, and room type. These findings highlight the necessity of including family involvement as a measurable dimension of educational quality. They also support policies and practices that systematically integrate this component into the evaluation and continuous improvement of early learning environments.