Jane Isabella was the sixth of ten children of Willam Giles and his first wife, Sarah (Roper). William Giles emigrated to SA in 1837 with his second wife Emily and their infant daughter, together with William's nine living childen from his first marriage. Jane was then 13. They lived for nearly two years at Kingscote, Kangaroo Island where William was Superintendent of the South Australian Company and, from 1838, Special Magistrate. William and Emily went on to have many more children, and among Jane's domestic duties were the family's baking and the care of the younger children.
When the SA Company moved its headquarters from Kangaroo Island to the mainland in 1939 William and his family moved to Adelaide. In 1842, when she was 18, Jane married Alfred Watts, a business manager and accountant. The first Marriage Act had just been passed, and their marriage was the first in the colony to be legally enacted by a non-conformist minister. They were married in the Congregational Church by the Rev'd Q T Stow. The couple lived in South Tce, and later at Leabrook. The Biographical Index of South Australians records only one child, Minnie.
Jane's book Family Life in South Australia gives an account of early life in SA. It is autobiographical but is written in the third person, referring to her father as 'Mr A.' and herself as 'Mr A's second daughter' and later as 'Mrs C'.