Amidst intensifying policy concerns with children's wellbeing and development, healthcare professionals are required not only to assess risk of abuse and neglect, but to manage risk of ‘poor parenting’ more broadly. Drawing on 15 in‐depth interviews and non‐participant observations of 61 professional‐family interactions, across four preventative public health services for children in the Netherlands, we explored how professionals accomplished such risk work amid intractable uncertainties. Building inferences from brief encounters with families, professionals gauged the extent to which they trusted parents to care ‘appropriately’. This trust developed most readily with parents experienced as ‘familiar’ by the largely middle‐class female professionals. Harnessing Schutzian phenomenology, we analyse the related manifestations of social structure within the interactional‐dynamics and lifeworlds of risk assessment. We argue that social structures of gender, class and ethnicity can be seen as influential both through the differing potential for ‘we‐relationships’ to be formed and via the generalising and stereotyped knowledge applied in their absence.