ABSTRACT Objective: to investigate the trajectory and follow-up of the health of children with diabetes mellitus type 1 in regard to the attention given by the different public health services and the relationships between the services, the child and their families, from the perspective of mothers and caregivers. Method: qualitative study with inductive thematic analysis, based on the theoretical references of vulnerability and health care networks, from in-depth interviews with 56 mothers or caregivers, in two Brazilian public health services. Results: reports marked by sufferings, challenges and notes show the centrality in the disease, fragile access, little resolution, insecurity in urgent and emergency situations and superficial bond with insufficient support to the family, and fragmentation. The specialized care is characterized by trust, the bond and the efforts to prevent the use of other health services. Conclusion: families and children are exposed to vulnerable circumstances in the longitudinal follow-up, with consequent distancing of network care. Thus, they indicate the need to expand the integration of care, intersectoral actions, social participation and coordination of care networks, in search of greater access and inclusion. Therefore, there are implications with political and financial efforts to advance access to comprehensive care and reduce vulnerabilities.