1810 A web tree gives Richard Blanc b1810, married Susan (b1808) d 27 Mar 1880. Richard had a sister Mary. (I don't know if there were more siblings) Their father was Robert Blanc 1774-1847 m?" (I cannot find this 1774 birth in the transcripts of the French Church Records put out by Huguenot Society). They had three children, Richard Blanc b1831 in Portarlington (married Mary Tersa Tighe in Dublin in 1861), Sarah Blanc born 1832 in Portarlington, and Susan Blanc born 21 Dec 1843 in Portarlington. This tree also puts Richard Blanc (b1810) father and mother as Robert Blanc (b1774-d1847) and Mary (b1780)
Another web poster states their great-great-grandfather was Robert Blanc born: 1834 Portarlington. He married Jane Gibson, born: 1844 Stradbelly Co. Laois Ireland. They immigrated to New Zealand around 1860.Robert worked the gold fields in the South Island; there were 8 siblings all together. Roberts parents are stated here to be Richard & Susan Blanc.
The above is at odds with the information from Jack Smallhorn who is descended from the Joshua Smallhorn in the above chart. On balance I think that Jack Smallhorn is good on data after 1850, but weak on the data before that, so I am inclined to put more faith in the charts on this page.