Living with a chronic health condition in the home can have a debilitating effect on the psychosocial and psychoaffective wellbeing of the entire family. This is particularly the case for healthy school aged siblings. This research investigated the perceptions and experiences of at-school support for well-siblings to evaluate its effectiveness in mitigating and minimising the at-home illness-related stress effect. Seven siblings (both primary and secondary age) whose brothers had received treatment for a chronic illness (e.g. cancer) were interviewed, as were their mothers, six schoolteachers, and two principals. Responses were analysed thematically, and the findings revealed that the chronic illness of a sibling bears strongly on how well-siblings feel about themselves: their very identity is challenged; and they lose their sense of belonging, worth, and self. Findings identified that inconsistencies in at-school support are linked with a lack of an overarching mandate for support, emphasising the need for urgent remediation in policy development and process reform.