I present Digital Sovereignty as the second dimension of the Quantum Child Framework, examining how children’s rights, agency, and identities are shaped within digital environments designed to capture attention, harvest data, and influence behaviour. These are complex terrains, influenced by family values, cultural norms, political contexts, and religious traditions. Around the world, academics, activists, and charitable organisations are pressing governments to prioritise this issue, yet progress remains uneven. Sovereignty, I argue, is not only about safeguarding children but also about power: the ability to choose, to consent, and to participate with awareness in shaping one’s life and world. Through case studies, I reveal both the erosion and reclamation of sovereignty, showing how children grapple with these challenges in real time. Developmentally, sovereignty emerges across childhood, from early acts of consent to pre-adolescent awareness of manipulative design, to adolescent advocacy for digital rights. I conclude by offering practical guidance and encouraging families to create their own strategies for cultivating sovereignty in ways that are authentic to their unique contexts.