Cindy,
Here’s the 1857 marriage in Desertcreat Church of Ireland, groom was from Glenlark and bride from Oughterard:
https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_returns/marriages_1857/09527/5453564.pdf
A William Carson farming in Oughterard in 1901:
http://www.census.nationalarchives.ie/pages/1901/Tyrone/The_Rock/Oughterard/1731700/
He’s probably Elizabeth’s brother. His father was also William according to his marriage certificate:
https://civilrecords.irishgenealogy.ie/churchrecords/images/marriage_returns/marriages_1876/11159/8088161.pdf
The above William was evidently in the RIC and met his wife in Cavan. Same family in 1911:
http://www.census.nationalarchives.ie/pages/1911/Tyrone/The_Rock/Oughterard/861340/
Mid Ulster Mail of 24th Oct 1925 reports William Carson’s death and his burial in the family burying ground at Desertcreat. The report says he had retired from the police on a pension to run the family farm and was well regarded in the community. His funeral got a large turn out. Many mourners named (see attached article).
The Mid Ulster Mail of 11th April 1942 has an in memoriam entry placed by William’s 2 daughters Florence & Ethel who were living at Oughterard, Bangor (Co. Down). It mentions that their mother had died on 8th Apr 1938.
Mid Ulster Mail of 23rd June 1951 mentions the death of William Archibald Carson, eldest son of William & Elizabeth, at his home in Cowes, Isle of Wight. Regretted by his sisters and brother.
Mid Ulster Mail of 13th April 1945 has an in memoriam placed by son John Carson and his wife Annie and “grandchildren.” Their address was 140 Sugarfield St, Belfast.
Tyrone Constitution of 16th May 1873 reports that William Sinclair of Glenlark was convicted of assault at Glenlark on Bridget Devlin and her daughter Mary. Reportedly their cattle had been trespassing on his farm. Sinclair received 14 days imprisonment with hard labour in each case and Sarah Sinclair was fined 5 shillings for assaulting Mary Devlin, Bridget Devlin junr was fine 5 shillings for an assault on Margaret Sinclair.
Tyrone Constitution of 15th Oct 1869 reports an assault on William Sinclair of Glenlark by Peter & John M’Cullagh and Patrick M’Cullagh. There had been an incident in the pub in Gorticastle involving a dispute over payment for some sheep. James Devlin had been assaulted by the M’Cullaghs and William Sinclair had “interfered to save Devlin, and for which he received considerable abuse as his appearance next day evidenced.” The M’Cullaghs were convicted and fined.
No Sinclairs in Glenlark by the 1901 census. The Valuation Revision records indicate William left the farm in 1878. (Plot 27 108 acres).
There are about 10 trees on Ancestry with some details of the Sinclair & Carson families.