Hi again SeonaighMacPherson. (Did I mention that it's GREAT to hear from you?

)
I have the marriage cert. They married in Glasgow, rather than Benbecula.

The date was 16 Jun 1876, Kelvin Parish, Glasgow. It looks like they were living in the same tenement house. I surmise that she had moved to Glasgow for work, possibly going with brother John. She was an asylum attendant at the time.
They are buried in Earlswood Cemetery: Stone 48 transcript: Angus died Feb 25, 1889, aged 54 yrs. Mary A. McPherson, beloved wife of Angus Graham died Jan 1, 1887, aged 33 years. Their children Hugh, died Aug 4, 1886 aged 6 months, Neil died June 6, 1884 aged 1 year and 3 months.
Their daughter Marion (sister to my g grandmother Annie) married a Morrow. Like most in this family, she died very young.
Morag "Marion" McLeod Graham
Birth 20 Jun 1877 in Glasgow, Lanarkshire, Scotland
Death 14 Mar 1909 in Fairmede, Saskatchewan, Canada
There is a Morrow remaining on the original homestead in the Wapella area. I have recently asked for an introduction through an intermediary on a neighboring farm.