Her mother, Frances Paca Dallam Peter, was related to William Paca who Governor Maryland and signed the United States Declaration of Independence. Her father, Robert Peter, a chemist, geologist, and physician, was a native of Cornwall, England. Robert Peter entered the United States in 1817 and relocated to Lexington in 1832 to attend Transylvania College. He obtained a medical degree from Transylvania in 1834. The next year Robert Peter and Frances Paca Dallam married and set up a household in Lexington. Robert held several positions at Transylvania including the chair of the pharmacy and chemistry departments, and dean of the faculty, librarian of the medical school, and editor of the medical school journal. During the United States Civil War, he was the senior surgeon for the United States Army in Lexington and was the administrator of the military hospitals in the area. Peter grew up in a family that had a leadership role in Lexington.