As societal needs change and STEM solutions are offered, an increasing concern for the participation of girls in STEM has emerged. Research has consistently shown the unintended preferential treatment of boys by teachers during STEM teaching and, although well recognised, has seen limited change over the past decades. Gendered interactions, including microaggressions, influence girls' identity formation from a young age, leading to a decrease in girls' STEM participation. This results in the ongoing trend of underrepresentation of women in STEM fields due to underlying gender equity issues. To improve this gender gap, it is important to consider the beginning of the STEM pipeline, the early stages of education. Drawing upon the system of concepts from the cultural-historical theory, this study explores the motivating conditions created by the Conceptual PlayWorld model for girls' engagement in STEM in the early years. Using a holistic study design, video observations of interactions and experiences within and outside the Conceptual PlayWorld were gathered from two preschool teachers and 13 children aged 2.3-3.2 years. Findings support previous research regarding the accumulation of microaggressions in free-play settings that position girls away from STEM activity. These are minimised inside the Conceptual PlayWorld due to the changed role of the teacher. It is argued that the possibilities afforded by this model positively shift interactional patterns to create motivating conditions for girls in STEM, allowing both girls and boys the opportunity to have a strong engagement and interest in STEM from the very beginning.