Hi Brodie
Welcome to RootsChat

The best place for you to start is to view William and Helen's marriage certificate on line at Scotlands People
www.scotlandspeople.gov.uk.
The cert. will include, amongst other info, their parents' names including mothers' maiden names which will let you hopefully trace their families.
There is only one marriage showing in the period you are looking at:
WILLIAM GRAHAM and HELEN THOMSON Marriage: 25 MAY 1866 Edinburgh Parish, Edinburgh, Midlothian
This looks like them in 1871:
William Graham 36, flax porter, b. Scoon
Hellen Graham 32, b. Lochio (spl), Forfarshire
Jessie D Graham 4, b. Dundee
James T Graham 3, b. Dundee
William Graham 1, b. Dundee
Address: Shaws Pend Cowgate, St Andrew Angus
Regards.
Monica
