Family caregivers provide essential care and support for individuals living with dementia, yet their contributions and needs are often unrecognized within formal health care systems. Over time, this marginalization can contribute to long-term trauma. Guided by a trauma-informed care (TIC) framework, we explored the experiences of 15 family caregivers in a longitudinal, qualitative study. Set in British Columbia, Canada, data were collected through semi-structured interviews and reflective diaries. Data were analyzed using inductive-deductive thematic analysis. Deductive analyses demonstrated that participants' experiences aligned with existing TIC principles. Inductive analysis identified "Uncertainty" as a novel principle, reflecting the ongoing challenges caregivers face from diagnosis to the inadequacy of in-home supports. Our study highlights the importance of recognizing trauma induced by interactions with formal health care services and the value of using a TIC approach with family caregivers of people living with dementia.