Alison,
The tithe applotment records for Crievaghy in 1832 list 6 Lough farms in the townland. Thomas had just over 8 acres. If Thomas was a farmer, you can probably definitely rule out the lady who died in Favour Royal. Apart from the fact that farmers didn’t move about much (save to emigrate), her death certificate would normally have said “farmer’s widow” or similar and not "labourer's widow."
http://titheapplotmentbooks.nationalarchives.ie/search/tab/home.jsp
Griffiths Valuation for Creevaghy in 1861 lists just 2 Lough farms (Francis & William). Thomas and the others had evidently either died or left the area and there had been some consolidation. There’s no widow Lough shown either. My hunch therefore is that both Thomas & Jane died pre 1861.
I had a search of the British Newspaper Archive site for any articles mentioning the Loughs and Creevaghy. Only one I could find was from the Fermanagh Herald of 16th July 1904 in which Francis Lough was selling 20 acres of meadow land.
The Loughs in Creevaghy are likely all related, and the repetition of the same names in each family was pretty common at that time.
1 Lough farm in Creevaghy in 1901:
http://www.census.nationalarchives.ie/pages/1901/Monaghan/Clones_Rural/Creevaghy/1630927/
Thomas Lough was the son of Francis Lough, and he married Martha Gillespie in 1859:
https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_re…
The above Thomas died in 1901. Here’s his probate abstract from the PRONI wills site:
Probate of the Will of Thomas Lough late of Creevaghy County Monaghan Farmer who died 21 July 1901 granted at Armagh to Francis Lough Farmer. The will is on-line and it mentions that he owned 3 farms. He left everything to his wife Martha. A Frank Lough of Legnakelly was one of the executors, so he’s presumably related to the family in some way (and will be the man advertising the land for sale, I expect).
There were evidently Loughs still farming there in 1949:
Lough David of Creevaghy Clones county Monaghan farmer died 13 December 1948 Probate Belfast 5 September to George Emerson Henderson solicitor. Effects £1236.
The above will is not on-line, but should be in PRONI in paper format. So you either need to go in person to see it or pay them to copy it.
Martha died in 1908 and again mentioned owning 3 farms, 1 in Creevaghy, 1 in Mullanacloy and the 3rd in Longfield. The farms were left to sons James & David and there was financial provision for other children. This will is on-line on the PRONI wills site.
I notice that the 1859 marriage between Thomas Lough & Martha Gillespie was held in Clogh Church of Ireland, which is in the parish of Clones but in Co. Fermanagh (Clough Rd, Roslea). Tradition was to marry in the bride’s church (after which she’d usually attend her husband’s). But in this case, I’d say that if you don’t find your family in the main Clones records, it’s worth checking the Clogh records too. There are several churches in the parish of Clones and they may not all be on-line. You may have to do some old fashioned research and look up the paper/microfilm records. Clogh has records as follows:
Baptisms, 1811-91; marriages, 1792-1910; burials, 1810-1986.
There is a copy in PRONI in Belfast. If you are unable to go yourself, you could employ a researcher. Researchers in the PRONI area: http://sgni.net