I have had a look in my records and I have the following
St Machar Cemetery, Aberdeen
John Mcleod Stewart - died 29/10/1938 (63 years)
Jessie Campbell Wattie - died 16/3/1940 (63 years)
Elizabeth Stewart - died 29/3/1916 (14 years)
John McLeod Stewart b 1907 in St Nicholas parish, aberdeen.
On deceased on line I found a Thomas Clyde Stewart Buried 10/11/1903 in Old Machar with 2 others in the same plot.
If you have a look on deceased on line you may find the rest of the family.
The gent who served in the 79th Highlanders, probably saw action in the Crimea and/or India during the 1850-1860's. You can get his records on the find my past website.
Hope this helps a bit