["Medical Anthropology Quarterly, EarlyView. ", "\nAbstract\nIn this ethnographic research project involving disabled and non/disabled siblings in Canada, we have found that during major life‐changing transitions, such as the death of a parent, siblings face many challenges, including structural and systemic inequalities, struggles with and within various service systems, and difficulties with emotions and mental health. In response to these challenges, siblings undertake “extraordinary measures” through co‐creative “sibling disability worldmaking” to imagine livable futures. During times of major transition, worldmaking is a strategy siblings use to navigate these upheavals and attempt to co‐create livable lives despite a lack of systemic support.\n"]