1851 Arbory
Ballanorris
Thomas Duggan head married 55 ag labourer b Arbory
Margaret wife married 48 b Arbory
Elizabeth daughter unmarried 24 dressmaker b Arbory
Margaret daughter unmarried 16 house servant b Arbory
Thomas 14 son shoemaker's apprentice b Arbory
William son 9 scholar b Arbory

Looks like Thomas died before the 1861 census
There is a Thomas Duggan buried in Arbory 28 Jan 1857 age 62

If this is the right fellow then he seems to be
Thomas ch 16 Oct 1796 Malew son of James Duggan and Margaret Callow who married
14 Jan 1792 Malew

1861 Census Index
DUGGAN
Arbory 1 60
Margaret 56 b Arbory
Thomas 25 b Arbory
William 19 b Arbory

1871 Census Index
Malew 6 6
DUGGAN
Margaret 66 b Arbory
Thomas 32 b Arbory
Margaret E 34 b Arbory
William H 8 b Arbory William Henry ch
20 OCT 1861 Arbory s/o James Duggan & Catherine Gelling md 17 Feb 1847 Arbory
This young Wm H was buried 1 Jan 1872 Arbory
His father James was s/o Thomas & Margaret Callow

I'll have to look farther to see when/where Margaret Callow Duggan died

Donna