Were your great great great grandmother's parents John Oates and Harriett Otley and were her grandparents Mark Oates and Mary Shaw.
On my great great great grandfather, Charles Oates's Conditional pardon [31 May 1853], it mentioned that he had a sister Sarah. Other siblings were John, possibly George, Betty, Ann, Harriet, Mary and Caroline.
Charles Oates came to Tasmania in 1844 as a convict aboard the Anson. He was convicted of stealing 7 sheep and sentenced to 15 years as a convict and he wasn't allowed to go back to England - he left behind a wife there Elizabeth Basion, the daughter of William Basion who was a shoemaker in Cartright street. In Tasmania he married Ann Jackson and they had 13 children.
Please feel free to email me more information on Sarah Oates and John Jefferson if the names mentioned in my post are also names you've found through your family history research.