My Hospital Buddy Ida: AR-CBT for Children With Cancer

The goal of this clinical trial is to learn if an augmented reality (AR) mobile app-based cognitive behavioral therapy (CBT) program can help children aged 6 to 12 years who are being treated for cancer cope with treatment-related distress and improve their quality of life. The main questions it aims to answer are: * Does an AR-supported CBT app improve health-related quality of life compared with the same CBT content delivered on paper, and compared with usual care? * Does the AR-CBT app improve resilience, emotional and behavioral functioning, anxiety, and treatment-related symptoms such as nausea and fatigue, compared with the other two groups? Researchers will compare three groups: an AR-CBT group using a smartphone/tablet app called "My Hospital Buddy Ida," a Standard CBT group receiving the same content through a printed workbook, and a usual care control group, to see if the AR app leads to greater improvement in quality of life and related outcomes. Participants will: * Be randomly assigned to one of the three groups * Complete a 12-module, 9-session CBT and Child Life program (AR-CBT and Standard CBT groups) or continue usual hospital care (control group) * Complete questionnaires about quality of life, resilience, emotional and behavioral symptoms, anxiety, and treatment-related symptoms before and after the program (approximately 9 to 12 weeks later)