Hi Kerri
Using information on your Lanarkshire topic Nicholas has a sister Isabella who married a David Ferguson in 1862. To find their parents download the marriage certificate from Scotlandspeople as that should have both parents including mothers maiden name.
Familysearch IGI has transcribed Scottish Births and Marriage indexes 1855 to 1875 direct from the Statutory Registers and this shows that the marriage was 9th July 1862 in Anderston, Glasgow but the names are D FERGUSON and Isbel KIRKWOOD. If you search SP using these exact spellings you will find the marriage.
Andy