This paper highlights the expertise of marginalised and underserved populations, placing them at the centre of understanding resilient information systems design. We present a collaborative project in which women experiencing homelessness, alongside researchers in information systems and healthcare sciences, co-produce digital health interventions aimed at addressing psychological distress and safety concerns. Homelessness is associated with exclusion, resource deprivation, trauma, and abuse. By learning from these deeply challenging lived experiences, marginalised and underserved communities offer invaluable insights into how information systems should be designed to support users during episodes of violence, trauma, and crisis. Key improvements include system covertness, robustness, responsiveness, timely activation, and personalised privacy settings. This study further provides critical insights into the value of collaborative, co-production-focused design research, illuminating the requirements of resilient information systems that serve a broader user base.