I think we are researching the origins of this ROBERTSON family in Scotland. Susan, and siblings (?) in the original post.....where are they in Census records in Scotland before arrival in Victoria.
Original post -
"Susan ROBERTSON born abt 1832 Perthshire. Came out to Australia with Margaret. Noted as youngest daughter of Donald Robertson, Perthshire when she married as a spinster in 1863 in her sisters/brother in laws house "Tasman" at Ceres. She was the second wife of John Cottle Ching (born Devon). They had Annie Robertson Ching......
...... Charles Cottle Ching (my gg grandfather)........
Laura Sophia Ching and Catherine Amelia Ching."
Geelong Advertiser 30 Jan 1863 p2
https://trove.nla.gov.au/newspaper/article/148905742?On the 29th January, at Tasman Cottage, Barrabool, the residence of Mr James Anderson, by the Rev. James McRoberts, Mr John C. CHING, Barrabool, son of Mr William CHING, Devonshire, England, to Susan, youngest daughter of Mr Donald ROBERTSON, Perthshire, Scotland
Wording suggests that Donald ROBERTSON, Perthshire is alive at Jan 1863.