Across social care, healthcare and public policy, enabled by the big data revolution (which has normalized large-scale data-based decision-making), there are moves to join up citizen databases to provide care workers with holistic views of families they support. In this context, questions of personal data privacy, security, access, control and (dis-)empowerment are critical considerations for system designers and policy makers alike. To explore the family perspective on this landscape of what we call Family Civic Data, we carried out ethnographic interviews with four North-East families. Our design-game-based interviews were effective for engaging both adults and children to talk about the impact of this dry, technical topic on their lives. Our findings, delivered in the form of design guidelines, show support for dynamic consent - families would feel most empowered if involved in an ongoing co-operative relationship with state welfare and civic authorities through shared interaction with their data.