Purpose: There is a critical need to understand how to attract Black girls and other girls of color to the science, technology, engineering, math, and computer science (STEM+CS) field. This study aims to look at the design and implementation of a CS learning ecosystem that supports girls of color in acquiring critical CS skills starting in middle school. Design/methodology/approach: This mixed-method case study included 53 girls, between the ages of 11 and 13, in four US middle schools. Study methods included the analysis of a pre-program student survey, longitudinal interviews and focus groups, weekly observations and computing artifacts. Findings: Program participants were interested in CS, were confident in their ability to learn CS, had prior coding and CS experience and had parents and teachers who encouraged them to learn CS. But some students showed dependent learning behaviors while engaging in CS activities. These included relying on instructors and being reticent to make mistakes--behaviors that limit learning. The CS learning ecosystem supported students as they shifted from applying dependent learning approaches to applying independent learning approaches. Instructors sustained a growth mindset and supported productive struggle as students learned CS skills. Originality/value: A CS learning system supported equitable learning experiences and helped students develop independent learning behaviors that led to deeper engagement in CS.