Re 1872 marriage in Whitburn
I wondered if Margaret Buchanan dau of Peter Buchanan and and Mary Arbuckle may have been a registrars error. ( i.e. Buchanan rather than Casey)
It appears not.
William Henderson and Margaret Buchanan had a son named John born in Cambusnethan on 14 Mar 1873.
However, Cambusnethan was exactly where Peter Casey and wife Mary Arbuckle lived at 1871 and it's also where this Peter died in 1873.
There are no other births showing for this couple and the child does match with the 1yr old who travelled aboard the Strathnaver with his parents in 1874.
Therefore: Margaret b Cambuslang circa 1854 shows on the 1861 census as Margaret Casey but seems to have married as Margaret Buchanan.
I also agree with a previous comment.
Think it was Forfarian?
As the 2nd daughter, her birth name may well have been Margaret Buchanan Casey.
Did anyone find this which provides further evidence that there was no father, step or otherwise named Buchanan
1851: Edinburgh Road, Baillieston
John Casey 72 B Ireland
Peter Casey 21Son B Old Monkland
Mary Anne Casey 18 Daughter in Law. Born CAMBUSLANG
This must be Mary Arbuckle and more or less proves that all of her children were born within this relationship/marriage
EDIT:
Would hazzard a guess that Mary Ann Arbuckle was the daughter of Andrew Arbuckle and Mary Shaw.
1841: Kirkhill, Cambuslang
Name Age
Andrew Arbuckle 40
Mary Arbuckle 35
George Arbuckle 15
Charles Arbuckle 15
Andrew Arbuckle 12
***Mary Arbuckle Jr 8
Agnes Arbuckle 5
Janet Arbuckle 1
Mary Arbuckle 7
Andrew and some of his children are in Shettleston at 1851 but no wife is in household.
Mary Shaw wife of Andrew Arbuckle is entered onto the Cambuslang Mortcloth date 9 Feb 1849.
She died from Cholera