The American Institutes for Research® (AIR®) partnered with Girls Who Code (GWC) to conduct an independent study evaluating the effectiveness of two GWC summer virtual programs, the Summer Immersion Program (SIP) and the Self-Paced Program (SPP), on promoting the pursuit of Computer Science (CS)-related postsecondary education for high school female and non-binary students. Employing a quasi-experimental design with inverse propensity score weighting technique, this study compared SIP and SPP participants with similar students who were waitlisted on the likelihood of majoring in a CS-related field. By analyzing publicly available National Student Clearinghouse data and GWC program records for the years 2020--2022, the study yielded two key findings. First, on average, both SIP and SPP participants were significantly more likely to major in a CS-related field (by 13.2 percentage points and 11.5 percentage points, respectively) than comparison students. Second, both SIP and SPP consistently demonstrated positive effects on majoring in a CS-related field across most of the student groups examined, including White, Black or African American, and Hispanic or Latinx students; students who are historically underrepresented in computing; and students with little to no prior CS knowledge. To enhance program outcomes, the study proposed to recommendations: (a) exploring supplementary feedback mechanisms to gather insights from participants, including program exit interviews, focus groups and long-term alumni surveys; and (b) establishing a comprehensive evaluation system to track the program's impact on various outcomes by including additional mid-term outcomes, such as enrollment in CS-related Advanced Placement courses and successful completion of these courses. This paper includes appendices detailing the technical aspects of the study and additional findings from In-Person SIP summer programs and a pilot program previously implemented by GWC before the introduction of the virtual programs.