This dissertation unpacks how feelings of loss and grief commonly experienced by parents of transgender and non-binary youth, which I call gendered mourning, give insight into the inner-workings of family gender systems. Diverging from the oversimplification that grieving a transgender child is transphobic, this research examines from where gendered mourning derives and illuminates the ways in which cisnormativity frames ideas of familial past, present, and future--setting parents up for feelings of loss. Observation at a support group for parents of transgender youth and in-depth interviews with attendees of the support group reveal that gendered mourning primarily involves feelings about a child's changing name and body, the trans child existing in a hostile world, and fears of losing a child through suicide. Additionally, this research explores how gendered mourning informs efforts to produce more livable social worlds for transgender youth. Through this, parents learn about gender diversity and simultaneously interrogate how hetero/cisnormativity impact their own lives, identities, and selfexpressions. This research positions cisnormativity, acting as a collective harm to us all, as the producer of loss instead of the transgender child.