Abstract Objective This mixed-methods study examined perceived acceptability and appropriateness of a novel digital mental health program targeting anxiety risk (i.e., perfectionism or error sensitivity) in 5-to-7-year-old children and their parents. Methods Parent–child dyads participated in a modular, web-based cognitive-behavioral program targeting negative overreactions to making mistakes. The program, “Making Mistakes”, consisted of a 6-month series of short video clips, journaling activities, and weekly reminders, and modules were delivered to caregivers and children separately. 86 dyads completed self-report measures, 18 of whom participated in semi-structured interviews, following completion of the primary program module. A standard thematic analysis was used to elucidate themes from the parent and child interview content. Results Our quantitative and qualitative results were generally aligned. Children and parents viewed the novel digital mental health program as acceptable and appropriate, favoring the cognitive behavioral strategies such as modeling positive reactions to mistakes, responding positively to child mistakes, and emphasizing effort over outcome. Participants also provided helpful feedback related to program content, delivery, and engagement, as well as suggestions to enhance the program. Conclusions Findings have implications for design and content features of parent-based and dyad-based programs, as well as digital mental health programs focused on reducing anxiety risk.