Many tools to assess coping in youth fail to engage youth meaningfully in the assessment process. This study aimed to evaluate a brief timeline activity as an interactive way to assess appraisal and coping in pediatric research and practice. We used a mixed method convergent design to collect and analyze survey and interview data from 231 youths aged 8-17 years in a community-based setting. The youth engaged readily in the timeline activity and found the activity easy to understand. Relationships among appraisal, coping, subjective well-being and depression were in the hypothesized directions, suggesting the tool supports a valid assessment of appraisals and coping in this age group. The timelining activity is well-accepted by youth and supports reflexivity, prompting youth to share insights on strengths and resilience. The tool may augment existing practices for assessing and intervening in youth mental health in research and practice.