Hi Nathan, and welcome to RootsChat.
I see that William Grieve and Elizabeth Craig were married in Smailholm, Roxburghshire, in 1867. Do you have a copy of that marriage certificate? If not, you need to get a copy, just to confirm that names of the parents of both William and Elizabeth.
You can get this at modest cost online at
www.scotlandspeople.gov.uk.
I see that the index there at SP says that Walter Grieve and Jean/Jane Ford had
Helen, baptised 24 March 1829 at Jedburgh
Helen, baptised 26 October 1831 at Jedburgh
John, baptised 23 June 1834 at Jedburgh
James, baptised 16 October 1836 at Jedburgh
In the 1841 census (transcription from
https://freecen1.freecen.org.uk/cgi/search.pl) they seem to be in Hobkirk
Address: Hallrule Porter Lodge
GRIEVE Walter M 35 Ag Lab Roxburghshire
GRIEVE Jean F 35 Roxburghshire
GRIEVE Robert M 15 Ag Lab Roxburghshire
GRIEVE Helen F 9 Roxburghshire
GRIEVE John M 7 Roxburghshire
GRIEVE James M 4 Roxburghshire
GRIEVE Isabella F 1 Roxburghshire
Adults' ages were supposed to be rounded down to the nearest 5 years in 1851, so Walter and Jean could be anything from 35 to 39, so they could have been born between 1801 and 1806.
In 1851 the family is at Nisbet Hill in Crailing, Jean shown as a widow
GRIEVE Jane Head W F 51 Prev Wife Of Ag Lab Berwickshire, Gordon
GRIEVE Elisabeth Dau U F 24 Farm Labourer Northumberland, Wark
GRIEVE Robert Son U M 23 Farm Labourer Roxburghshire, Ancrum
GRIEVE William Son U M 21 Farm Labourer Roxburghshire, Minto
GRIEVE Helen Dau U F 18 Farm Labourer Roxburghshire, Jedburgh
GRIEVE John Son U M 16 Farm Labourer Roxburghshire, Jedburgh
GRIEVE James Son U M 13 At Home Roxburghshire, Jedburgh
GRIEVE Isabella Dau U F 11 At Home Roxburghshire, Minto
Never trust anything you find online, including me! Always check by looking up the original documents at Scotland's People.