I think it is a given that you have to order one of the English born children's birth regs to confirm Jane's maiden name.
Don't want to be neg (my philosophy in genealogy is never say never never

) but I think you may struggle to find a Scottish marriage for John and wife Jane and sadly also a birth or christening for Margaret (who very much looks to me to have been born pre 1855 and the start of official registration in Scotland).
Only about a third of BMDs were registered in parish registers pre 1855 for all sorts of reasons (not sure what the equivalent % may be in England pre 1837). It may be that either the events of the marriage and/or Margaret's birth/christening were not registered at all...or registers have been lost or the family registered outside of the established Church of Scotland etc (Lodger I think has already mentioned this earlier).
The area of Cambusnethan is prime mining area, given the occupation of John Norman. Every reason for him to have spent some time after 1851 there working.
Closest I could see as a possible for Jane in 1851 was this entry:
Margaret Mckinnon 49 b. Shotts Lanarkshire
Charles Webster 23 coal miner b. Shotts Lanarkshire
Jane Webster 17 lace worker b. Shotts Lanarkshire
Euphemia Webster 14 lace worker b. Shotts Lanarkshire
John Webster 11 coal miner b. Shotts Lanarkshire
James Jack 40 lodger coal miner
Address: Wilsons Rows, Wishaw
From 1841 for this family, likely some children who show then have died and husband James Webster, a coal miner.
Not sure though how to prove this is the right family for Jane

Monica