Hi Coonwarra
The family seem relatively well documented on the IGI at
www.familysearch.orgFirstly, there are two births showing for a James Snadden at Bo'ness, West Lothian:
1. 28 Mar. 1813 to George Snadden and Elizabeth Robertson
2. 31 Oct. 1813 to Richard Snadden and Margaret Snadden
Given the names of James and Margaret Whitelaw's children, No.1 is the most likely entry for him.
There is a marriage entry for a James Snaddon and Margaret Whitlaw on 01 Mar 1833 in Old Monkland, Lanark.
I also did a parent search to see what children were showing for James and Margaret. On Family Search you have:
1. George 1834
2. Mary Young 1836
3. James Whitelaw 1838
4. William 1842
5. Elizabeth 1849
6. Jane 1856
These are a combination of actual extracted birth/christening record entries and submitted records. There were no entries showing for the births of Samuel, John, and Robert. If you have a look on the IGI you will get the birth places (all in Lanark) and specific dates.
For Mary Whitelaw, there are a number of entries for births in 1814 in Lanark. There was one in particular that caught my eye. There is an actual birth extract entry for the birth of a Margaret Whitlaw to a James Whitlaw and Mary Young on 24 July 1814 in Old Monkland, Lanark. Given the name of James and Margaret's first born daughter (according to IGI actual extracted birth records) being Mary Young Snaddon looks promising.
Regards.
Monica
PS. A parent search for George Snadden and Elizabeth Robertson shows probably James's siblings. The same for James Whitlaw and Mary Young with Margaret's likely siblings.