Background and Context: Historically, women have been underrepresented in computer science. To address this gender gap, researchers advocate for high-quality computer science programs for early childhood. Objectives: This study examines gender differences in coding performance before and after implementing a 24-lesson visual programming curriculum using ScratchJr. The curriculum's key features are summarized based on teachers' observations of student reactions. Method: Using a mixed methods approach, the study employs quantitative analysis to assess gender differences in pre and post assessments, while qualitative analysis explores the impact of the curriculum on girls' and boys' coding performance. Findings: The findings reveal comparable coding proficiency between boys and girls. Teacher interviews highlight aspects of the curriculum that reduced gender stereotypes, such as student engagement, autonomy, debugging practice, and collaborative exploration. Implications: Policymakers should prioritize high-quality computer science programs in early childhood to combat gender-interest stereotypes and promote confidence, emotional strengths, perseverance, and collaboration through open-ended coding projects.