hello Stephen from Melbourne
We have in our records that James Roberts, son of William Roberts and Margaret Greenhorn, was born in 1823 in Falkirk, Stirlingshire, Scotland, and he died on 19th of June 1891, 7hr 30m am, in Braes of Yetts, Dumbartonshire, Scotland. He married Agnes Lang in 1840.
Agnes Lang was born in 1817 in Cadder, Lanarkshire, Scotland. She died on 11 March 1866 in Noon, Barhill Rows, Twedras, Kirkintillock, Dumbartonshire, Scotland but we have no further details about her parents.
Agnes Lang and James Roberts had nine children. Sinclair appears to be indicative of an area in Scotland which was used to preserve family connection and heritage, rather than a surname, as we had a similar problem researching a descendant, Muriel Irene Sinclair Gibson, daughter of John James Gibson and Euphemia Gartshore Roberts (descendants of James Roberts.) Muriel Irene Sinclair Gibson was born 1905 in Beulah, Victoria.
We have relatives in Victoria who are descended from the Gibson, Lang and Roberts families, who have conducted research into the ancestry, so if you are interested in finding out more information please contact me for further contact details / email address.