This study is recruiting non-metastatic breast cancer survivors who were diagnosed between ages 18 and 51 and are currently 6 months to 5 years post-treatment. Eligible participants must have a score of 5–14 on the PHQ-8 depression screening tool. This study is testing a digital mindfulness meditation-based program. "Investigational" means it has not been approved by the United States Food and Drug Administration (FDA). Participants will be randomly assigned (like drawing one number out of three at random) to one of three groups: (1) live online mindfulness classes over Zoom, (2) a specially designed mindfulness app, or (3) guided audio meditations. The primary purpose of this study is to determine if different ways of delivering digital mindfulness training can improve mental health and well-being in younger breast cancer survivors. The program is delivered either by live online sessions, through a mobile app, or by listening to guided meditation recordings. Participants can expect to be in this study for about 9 months, including a 6-week training program and questionnaires before, during, and after training. Participants will be enrolled for a duration of 9 months, and a total of 15 patients will be recruited locally over the course of 36 months.