ABSTRACT Family interventions have been introduced in several European countries as social inclusion measures for disadvantaged families. Compared with adult social work, in social work for families, social workers aim to utilise a whole-family approach; they follow up all family members, acknowledge multiple target areas and coordinate the services for the families. This cluster-randomised study (ClinicalTrials.gov: NCT03102775) with a mixed methods approach analyses children’s involvement in family interventions and compares child-related effects of governmental (the HOLF model) and local family intervention practices in Norway. The data are based on a cluster-randomised study involving 29 Labour and Welfare offices and baseline and follow-up questionnaires for parents (N = 862). We conducted in-depth interviews with family coordinators to help us understand how children are involved and how their involvement may contribute to any improvements. While there were no effects of using the HOLF model compared with local family intervention practices, results indicate that the family intervention seems to contribute to increasing children’s involvement with welfare services and improving their access to welfare support. The interviews demonstrate the potential of a genuine whole-family approach, where children are directly involved in the family intervention practices. Trial registration: ClinicalTrials.gov identifier: NCT03102775