RecruitingBehavioural interventionHealthy Weight Intervention Families During ALL Treatment: NOURISH-ALLThe purpose of this study is to conduct a single arm pilot of the NOURISH-ALL (Nourishing Our Understanding of Role modeling to Improve Support and Health in Acute Lymphoblastic Leukemia) intervention focused on three components of participant engagement. This is a single arm intervention study that involves participation in a 6-session family intervention and three time points of multimethod data collection. The primary outcome is participant engagement, measured as recruitment, retention, and intended dose received. This study will be conducted over 5 years in three phases: * Aim 1a: Adapting the NOURISH-ALL Intervention for Families of Youth with ALL (Year 1) * Aim 1b: Iteratively Refining the NOURISH-ALL Intervention (Year 2) * Aim 2: Pilot Single-Arm Trial of NOURISH-ALL Focused on Participant Engagement (Years 3-5)