Hello Edward and greetings from Waterford in the Sunny South east of Ireland
I had a quick look on rootsireland.ie which includes a database of Waterford parish registers. I found a marriage of Maurice Donohue and Alice Couming in 1886 in Kilgobnait RC parish. I also found in the same parish baptisms of their children Mary (1887) and John (1888). To obtain further details check out the above website (pay per view) or drop me a line at waterfordorigins@gmail.com
I see that the Maurice Donoghue found in the townland of Cushcam in 1901 was a widower with three young children at the time. He was a blacksmith and they were living in a one roomed house with one window to the front. In 1911 he was listed as a servant in the house of James Moloney at Ballymacmague. His children are not listed in the household.
The Waterford death registers - online at Waterford County Library website - list the death on 23 April 1892 of John Cowney, a 63 year old labourer of Ballyeighteragh (in the parish of Kilgobinet about 3 miles from Cushcam). The informant is his daughter Alice Donohue of the same place. Evidentally this is your Alice Couming.
Hope the above is of help to you. Always happy to help the Wandering Waterfordians find their way home!
Warm wishes
Tony Hennessy