Young mothers are more likely to access healthcare for their children in emergent care settings and less likely to use preventive care. This study examines the healthcare-seeking behaviours of young mothers to inform the design of tailored interventions. Semi-structured interviews with nine young mothers (aged ≤ 25 years) who were attending a supported playgroup in Brisbane, Australia were conducted and explored using the Capability, Opportunity and Motivation and Behaviour (COM-B) model and the Theoretical Domains Framework (TDF). Five behavioural themes were identified (navigating the system, complex referral pathways, delays and long wait times, understanding child development, and connecting to services) and the role of the supported playgroup in shaping young mothers’ understanding of child development and connecting them to services was highlighted. Recommended strategies to address these factors include opportunities for young mothers to learn about child developmental milestones, improving young mothers’ health literacy, increasing young mothers’ skills and/or the availability of support to help them navigate health services, and providing more accessible entry points for child assessments, referrals, or early intervention programs.