Hi Janet (and Linda, if you are still following this thread),
Thank you for this, as it is the most useful thing I have found on these Somervilles in a long time. I am descended from William Somerville, farmer of Fassagh (c.1805-1893, died at Hanagh), and his wife Fanny, through their son David (1843-1900), who married Maria Stephenson in 1872, and David's daughter Annie Jane, my great-grandmother, who went to New York. I have been trying for years to work out how William fits with Alexander and Lowry, as the three of them farmed side by side at Fassagh and Gortnalee and I have always suspected they were brothers.
What I have found so far points two ways. A William was baptised at Inishmacsaint on 17 May 1807, son of Thomas Somerville and Margaret Watson of Drumbadmeen (Thomas married Margaret, daughter of Alexander Watson of Dromore, at Drumhome in 1792), and the 1796 freeholders list has both a Thomas and a William Somervill at Drumbadmean. So my William may be Thomas's son, or he may be a third son of your William and Ann, and Thomas and your William were clearly close relatives either way.
Would you be willing to share where the details for William (c.1752-1819, buried at Derrygonnelly) and Ann come from, for example whether the burial gives an age or townland, whether Ann's maiden name is known, and whether they had other children, especially a William, Thomas or John? It would also be really helpful to know whether you or anyone in your line has done a DNA test (Ancestry, MyHeritage, FamilyTreeDNA or GEDmatch), as my cousin's results are on GEDmatch and a comparison with Lowry's descendants could settle whether my William was his brother.
In return I am happy to share what I have, including Lowry's 1879 administration (granted to his daughter Jane McBrien of Roscor), the 1870 administration for his son William, Alexander's second family with Jane (including his son William who married Sidney Tichborne in 1874), and a lot of tithe, freeholder and burial records for Drumbadmeen, Drummenagh More and Fassagh.
Best wishes,
Kris