  Many children in foster care experience trauma that is rooted in unstable
family relationships. Other members of the foster care system like foster
parents and social workers face secondary trauma. Drawing on 10 years of Reddit
data, we used a mixed methods approach to analyze how different members of the
foster care system find support and similar experiences at the intersection of
two Reddit communities - foster care, and abuse. Users who cross this boundary
focus on trauma experiences specific to different roles in foster care. While
representing a small number of users, boundary crossing users contribute
heavily to both communities, and, compared to matching users, receive higher
scores and more replies. We explore the roles boundary crossing users have both
in the online community and in the context of foster care. Finally, we present
design recommendations that would support trauma survivors find communities
more suited to their personal experiences.
