This research paper aims to present the results of the implementation of the C.W.-SMILE tool that recorded child well-being in the second semester of the 2020–2021 school year. This is the fifth round of this ongoing diachronic research. The C.W.-SMILE tool consists of six dimensions: home conditions (D.1), nutrition (D.2), unemployment of guardians (D.3), free healthcare (D.4), moral education (D.5), and leisure (D.6). The first three dimensions concern children’s economic well-being, while the latter three dimensions determine children’s non-economic well-being. Based on welfare economics, the combination of economic well-being and non-economic well-being constitutes children’s general (social) well-being. Each dimension consists of Simple Indicators. The paper also presents the results of the school year as a whole, to help investigate the evolving impact of the COVID-19 pandemic on children’s well-being for more periods. The tool was used to measure the well-being of children in Attica, through questionnaires that were circulated in 22 public schools and three support centers of the organization ‘The Smile of the Child’ (25 units in total). The sample consisted of 509 children, belonging to three distinct school categories. The results of the second semester are mapped in seven clusters (relating to seven socio-economically homogenous groups of municipalities in Attica). Analysis of the results of the school year 2020–2021 was done based on the data collected from a sample of 1,623 children; in other words, it took into account the data relating to the entire samples that were surveyed in the first and second semesters. The central outcomes of all the previous rounds of the research are verified through a principal component analysis (PCA), and a multiple correspondence analysis (MCA) which are employed for the fifth round. Finally, the paper suggests an action plan of social welfare based on a ChoiCo game designed for the needs of the fifth round of the C.W.-SMILE research.