Hi Valerie
The aunt Jane, widow, (whose household 26 year old lead miner Thomas Taggart is staying in at Gibdale on the 1851 census) rang a bell when you said that she was a Jane Kermode who married William Taggart.
My g g grandmother, Eleanor Kermode (1805-1893, dau of Thomas Kermode and Catherine Moore of Ballafesson, Rushen) had an older sister, Jane Kermode b 1793 who married a William Taggart.
I looked for Jane and William on my "saved" pages of ancestry and found that in 1841 they lived at Gibdale, Malew, and that in addition to their children (Jane 16, Catherine 15 and Eleanor 7) there was also an old lady, Catherine Taggart aged 90 who, if she was the mother of William, would be your Thomas Taggart's grandmother.
The IGI has a William Taggart bap Malew 6 Jan 1781, parents Robert Taggart and Cath Killey. Other children of Robt and Cath are:
John 30 Aug 1767
Margaret 8 Oct 1769 / d 6 Sept 1773
Elizabeth 18 April 1773
Margaret 17 Dec 1775
Robert 23 Aug 1778
William 6 Jan 1781
Ann 17 Nov 1782
It's worth looking at Robert and John as possible parents of your Thomas b 1826.
Incidentally, in the household next door to Wm and Jane's family in 1841, there are 2 young ag labs, James Taggart age 20 and William Taggart age 15.
Jean