This paper analyses a sample of online discussions to evaluate the development of adult learners as reflective practitioners within a networked learning community. The context for our study is a blended learning course offering post-experience professional training to non-traditional university students. These students are parents and carers of people with autistic spectrum disorder (ASD). We use Lave and Wenger's "communities of practice" as a theoretical framework for establishing how students develop a learning community based upon mutual engagement, joint enterprise and shared repertoires. Those three aspects are analysed according to two measures. The first focuses on learner appropriation of the professional discourse, values and goals of the ASD carer through the network. The second relates to changes in the quality of collaborative activity over time. Our analysis demonstrates that students belong to an overarching community of practice, with different subsets who work at sharing and co-constructing common understandings. This shared discourse and common notions of what constitutes good practice help create a safe interaction space for the students. Once group identity is consolidated, more challenging questions emerge and the group are able to define further common values, understandings and goals through processes of resolution.