Hi linet,
You can search parts of the 1841 census on FreeCEN at:
http://www.freecen.org.uk/The full census is available on the (pay per view) site ScotlandsPeople at:
http://www.scotlandspeople.gov.uk/According to the IGI (International Genealogical Index) on the FamilySearch site at:
http://www.familysearch.org/James MCGREGOR and Margaret PEACOCK were not married in Hawick but in Selkirk (or, at least, Banns were called in Selkirk):
*James MCGREGOR m Margaret PEACOCK, 26 Nov 1830, Selkirk, Selkirk
Children to the couple listed on the IGI are:
*David MCGREGOR born 4 May 1831 Selkirk
*Jean MCGREGOR baptized 11 May 1834 Selkirk
*Joseph MCGREGOR baptized 5 Aug 1838 Selkirk
Do you know where in Australia they arrived? The answer to your question about passenger lists (which could at least indicate their date of arrival) depends on the state.
Regards,
JAP
PS: Given Scottish naming customs, James might well be the James MCGREGER (sic), son of David MCGREGER & Jean FLETCHER, born 30 Dec 1805 in Selkirk. There is also a record for a James MCGRIGOR, born 30 Dec 1805 in Edinburgh Parish, Edinburgh, Midlothian (Jean's given name listed as Jane).
David & Jean were married 20 May 1804, St Cuthberts, Edinburgh, Midlothian.
And Margaret PEACOCK might well be the Margaret PEACOCK, daughter of Joseph PEACOCK & Jean MILLER, bap 15 Dec 1809, Hawick, Roxburgh. There are a number of other children to the couple listed on the IGI.
Joseph PEACOCK & Jane (sic) MILLER were married 22 Sep 1798, Hawick, Roxburgh