The COVID-19 pandemic was a source of significant stress due to health and safety concerns and measures to control the virus’ spread, such as mobility restrictions. This measure was especially demanding for parents with school aged children, who had to find new work–family balance as their children participate in online education while attempting to work remotely. To evaluate parents’ stress trajectories during the pandemic, we conducted Ecological Momentary Assessments (EMAs) during lockdown for 29 days in 68 families in Santiago, Chile. In addition, we evaluated the role of educational level and income, co-parenting, and number of children in parents’ stress trajectories. Our results showed that during the first weeks of lockdown expected protective factors (i.e., income and co-parental support) were not able to influence parents’ daily stress management. Moreover, parents with higher educational levels reported worse stress adaptation than less educated parents. On the other hand, co-parental conflict was significantly associated with parent’s stress. Our study captured an acute response to COVID-19 related challenges. This study contributes to understanding how parents adjust to stress during adverse circumstances such as the COVID-19 pandemic.