Nancy Kroydon was the presiding officer of National Catastrophe Relief Auxiliary - Response Unit MD-478 before, during, and after the Great War.
According to the logs found on a terminal in the abandoned evacuation center at the Germantown police HQ, Nancy and her unit were deployed to the area on evacuation detail before the bombs fell. Over time, Nancy and her unit struggled to treat the many radiation poisoning victims. At least two nurses under Nancy's command deserted to try and get into a Vault or find out if their families had survived.
A detachment of the National Guard were deployed to Germantown to maintain order, but they eventually died or deserted, leaving Nancy and her unit on their own. As patients continued to die and even more became sick, Nancy started losing her hair and skin and eventually passed away.
Nancy Kroydon is mentioned only in Fallout 3.