This review analyzes Maria Lyra’s significant contribution to developmental psychology, focusing on her dynamic and semiotic perspective on early communication. Her EEA (Establishment, Extension, and Abbreviation) model describes mother–infant communication as a historically constructed, emergent, self-organized system, emphasizing shared meaning-making. Utilizing microgenetic analysis, the approach meticulously captures the subtle, moment-by-moment dynamics of mother–infant interactions. Lyra’s framework offers a powerful, nonlinear alternative to traditional views, applicable beyond early interactions and integrating diverse theoretical perspectives. Her work is praised for its originality, rigor, and enduring relevance.