The phenomenon of women's underrepresentation in computer science programs at Germany's universities and colleges can be examined from two perspectives. The negative factors why women decide against such studies have been considered in various scientific research papers. The aim of this paper is to uncover the positive factors why women decide to study computer science. Using Kathy Charmaz's Constructivist Grounded Theory, an initial theory or taxonomy will be designed to do this. For the data genesis $5$ female students of the University of Stuttgart were interviewed to find out their motivations and decisions. The parallel coding analysis and initial theory building revealed a total of $5$ central factors. Interest development, which defines initiation to identification, specification, and differentiation from other interests. Related to this is the self-efficacy process, which is the development of inner conviction in one's ability to overcome difficult challenges. As the third factor of personality unfolding belongs the autonomy process, which accompanies the independence of female students until the beginning of their studies. In addition, two other factors were found. Convergence describes the convergence of both parties, which are characterized by points of contact. The decisive factor is not the number, but the intensity of the promotion of interest. Last factor describes the STEM skills, which specifically concerns the mathematical understanding of the female students. Regarding computer science, the five factors have a strong coherence, which can influence each other both negatively and positively. Knowledge of the factors and their degree of influence from outside can be used to target promotions to attract more women to such studies.