Amelia Ryerse was born 19 February 1798, in Port Ryerse, ON, to Colonel Samuel Ryerse, an United Empire Loyalist, and his second wife, Sarah Underhill. She married Captain John Harris on 28 June 1815, less than six weeks after their first meeting. John was a veteran of the War of 1812, and was stationed in Kingston charting the Great Lakes. Amelia and John lived in Kingston and Port Ryerse for the first twenty years of their marriage, during which time they had ten children (eight of whom survived to adulthood). Two more children were born after they moved to London.

The Harris family settled in London in 1834, occupying Eldon House, which John had built for his family. They lived the typical life of a wealthy family of the 19th century, with three sons becoming lawyers and the daughters marrying well. John Harris died in 1850, leaving Amelia as the head of the family, a position in the family she maintained for thirty-two years. Amelia was devoted to her children and expended much of her energy in helping them to find success, health and happiness. She was devastated by the deaths of her daughters Charlotte (in 1854) and Helen (in 1860), and son John (in 1861), and was very involved in the lives and marriages of her other children. In May, 1857, her eldest son, John, went to England for medical treatment. While he was there Amelia began to write daily letters to him, detailing the activities of the family. This grew into her diaries, which she began on 12 September 1857, and continued until a the month before her death. More than merely a record of her activites, Amelia's diaries are a running commentary on her life and society. The diary was usually left open on a table in the drawing room at Eldon House, and it was through the diary that she gave news and instructions to her children and family. Her influence extended to her daughter Charlotte, two daughters-in-law Sophie and Lucy, and granddaughter Amelia Archange, who also kept diaries which provide even deeper insight into the world of the women of Eldon House.

In her later years Amelia grew lonely and depressed as she saw her children grow, marry, move away and die. She interpreted her own dreams and was preoccupied with death. The last entry was made in her diary on 25 February 1882, and she died a month later, on 24 March 1882.