The COVID-19 pandemic closed schools and childcare centers across the U.S., forcing many parents to care for children at home. While parents generally enjoy time with children and want more “family time,” evidence also suggests that substantial, unanticipated increases in parenting time may negatively impact at least some mothers’ well-being. We investigate this possibility using surveys (N=139) and in-depth interviews (N=65) with mothers of young children in Southern Indiana conducted during the COVID-19 pandemic (April-May 2020). We find that mothers who have greatly increased the time they spend caring for their children also disproportionately report increased stress, anxiety, and frustrations with their children. Our qualitative data reveal that disruptions in childcare arrangements, particularly when coupled with intensive work pressures and/or intensive parenting norms, exacerbate the negative impact of increased parenting time on mothers’ well-being. Meanwhile, other mothers are not experiencing increased parenting time as a substantial source of stress, and some are even experiencing increased parenting time as a source of joy in otherwise difficult times. We discuss the implications of these findings for research on parenting and its impact on women’s health and labor force participation, as well as for policies to support families during and after the COVID-19 pandemic.