Newton (Cambuslang)? & Crofthead (Carnwath)? appear to both be in South Lanarkshire
Don't go down that road unless you want to confuse things further.
As I have already pointed out there are several different places called Crofthead in Lanarkshire. Newton is an even commoner place name than Crofthead, and Cambuslang is not in Glasgow. It is an entirely separate parish and doesn't even have a mutual boundary with Glasgow.
As far as I can tell, you have three sources of information.
One is the transcription of the passenger list from the 'Strathnaver' which lists William, a miner, of Linlithgow, aged 24; Margaret, 20; John, 1; John, 20, unmarried; Isabella, 11. As other passengers' listings contain the county they came from, I agree that it is reasonable to suppose that in this case Linlithgow means the County of Linlithgow, that is, West Lothian.
Next is Margaret's death certificate which says she died on 14 September 1934, aged 81; that her parents were William Casey, miner, and Mary, surname unknown; she was first married at 18 in Scotland to William Henderson and had 9 surviving children, aged 61, 59, 53, 50, 49, 47, 46 and 40
Also you have a supposed date for the marriage of William and Margaret, on 23 June 1872 at Crofthead, which is not matched by anything in the Scotland's People database or the index to that database at FamilySearch.
- What is the source for this marriage date?You listed William and Margaret's children as William b 26 February 1877, Margaret b 7 September 1879, Peter b 28 March 1881, Isabella b 25 December 1883 and James b 29 June 1890, which is five. Add on John, who was aged 1 when they arrived in New Zealand, and that makes six. So there must have been at least three more to make up the 9 surviving at her death. Possibly more if one or more children predeceased their mother.
The NZ birth records list 22 children with surname Henderson, father William and mother Margaret. Four can be eliminated because one or other parent had a middle name, leaving 18 whose father was plain William and mother plain Margaret.
John, 1874
Mary, 1875
Margaret Ann, 1875
John Dunnett, 1875
George, 1876
William, 1877
William, 1877
Elizabeth, 1877
Margaret, 1879
Alexander Meanock, 1879
Peter, 1881
Benjamina Jessie, 1882
James, 1883
Isabella, 1884
William Alexander Procter, 1885
Amelia Florence, 1886
Elizabeth Anne, 1888
James, 1890
From the dates there have to be at least two different families, possibly three or more, but I can't sort them out from the NZ birth indexes. Maybe someone with better knowledge of how the NZ registers are organised might be able to tell?
Now for a bit of speculation. It could be, for instance, that Mary b 1875 is also their daughter, named after Margaret's mother. Mary would have been 59 in 1934, which is an exact match for a daughter of Margaret's listed on her death certificate.
If so, then their first four children were John, Mary, William and Margaret. First daughter named for mother's mother and second son named for mother's father? If so, William's parents would have been John and Margaret.
Their daughter Margaret b 1879 would have been 55 when her mother Margaret nee Casey died, so it looks as if Margaret b 1879 may have predeceased her mother.
Could the son aged 49 then be William Alexander Procter, and if so, why the middle names?
And was the 46-year-old daughter Elizabeth Anne?
Also, there is no birth of a Barbara, and it was their sixth son who was named James, so from this evidence also I don't think it's likely that William was the grandson of Barbara Smith.
There are far too many Isabella Hendersons in the Scottish birth indexes in 1862/1863 who could be the 11-year-old one in the ship passenger list.
