and yet more:
This explains why I couldn't find a marriage:
1901 census
9 Kinloch Street, St Clement, Dundee
282/3 ED 18A Household No 378
John Hughes, 28, calendar worker (?)
Elizabeth, 33, calendar worker's wife, b. Lochee, Forfarshire*
Edward, 4, b. Lochee
Agnes, 3, b. Lochee
John, 1, b. Dundee
May E Ross, 16, jute spinner, b. England
William Ross, 15, rove jute spinner shifter (?), b. England
Thomas Ross, 14, scholar, b. England
* note that Lochee is an area of Dundee