Objective: College students, especially females, reported worsened mental health during the COVID-19 pandemic. This multigroup comparative study aimed to explore stress and resilience of female college students between in-person and online enrolments, as well as with and without mental health diagnoses, at early and later stages of the pandemic. Method: Participants were 32 female undergraduate students (M[subscript age] = 23.75, SD = 6.13) from three classes -- Spring 2020 in-person, Spring 2020 exclusively online, and Spring 2021 exclusively online enrolments -- in a midwestern regional university in the U.S. They completed two surveys, four weeks apart between Times 1 and 2, quantitatively and qualitatively assessing perceived stressors, stress levels, and resilience. Frequency analyses, Wilcoxon signed-rank tests, and Mann-Whitney U tests were conducted by class. Results: Overall, the most reported stressors in Time 1/Time 2 were school (25.83%/26.36%), family (16.67%/18.33%), and lifestyle (16.67%/15.00%). On average, students with mental health diagnoses perceived more stressors, especially at the onset of the pandemic, than those without. Findings were presented and interpreted using cross-case analysis, suggesting that the pandemic stress and resilience depended upon students' enrolment format and associated stressors. Conclusions: This study offered practical implications for addressing student stressors during a crisis, across in-person and online enrolments, through targeted interventions.