By storing data about citizens for the purposes of service provision, private and public organizations have disempowered the people they serve, shifting the balance of power toward themselves as data holders. Through three co-production engagements involving families receiving ‘early help’ support from their local authority and support workers involved in supplying this care, we have identified existing data usage practices, explored the impact of those practices upon the supported families, and co-designed new and improved approaches - both technological and practice-based - that are perceived to offer families fairer treatment, greater influence, and to benefit from better decision-making. Our findings show that by applying Human-Data Interaction and giving supported families direct access to see and manipulate their own data, both during and outside of the support engagement, the locus of decision-making could be shifted towards the data subject.