I am not researching these folk, but I can respond with the following information anyway:
- 13 July 1889, at Clifferna RC Church (St. Michael's in Larah RC parish?), Mary Casserly living in the townland of Carrickacroman, daughter of Thomas a farmer, married Patrick Farrelly living in the neighbouring townland of Carrickallen:
https://www.irishgenealogy.ie/files/civil/marriage_returns/marriages_1889/10751/5920641.pdf- 31 January 1891, at Larah RC Church, Anne Casserly living in the townland of Carrickacroman, daughter of Thomas a farmer, married Patrick Smith living in the townland of Ratrussan:
https://www.irishgenealogy.ie/files/civil/marriage_returns/marriages_1891/10660/5884385.pdf- 1 November 1893, at Larah RC Church, Bridget Casserly living in the townland of Carrickacroman, daughter of Thomas a farmer, married Terence Smith living in the townland of Ratrussan:
https://www.irishgenealogy.ie/files/civil/marriage_returns/marriages_1893/10617/5868101.pdfSignificantly, further to these civil records, note that transcripts of the corresponding church records of marriage I've seen (in a website I subscribe to) additionally and usefully record the identity of the bride's mother in each case, the name recorded being Margaret Kelly. So a match for the couple you mentioned.
Here is Carrickacroman:
https://www.townlands.ie/cavan/tullygarvey/larah/larah-south/carrickacroman/Here is a civil birth registration for a Margaret "Casselly" born at Carrickacroman on 27 April 1866 to Thomas Casselly and Margaret Kelly:
https://www.irishgenealogy.ie/files/civil/birth_returns/births_1866/03527/2298039.pdfLikewise a civil birth registration for a Thomas "Casely" born at Carrickacroman on 17 April 1867 to Thomas Casely and Margaret Kelly:
https://www.irishgenealogy.ie/files/civil/birth_returns/births_1867/03483/2280308.pdfThe death of Thomas Casserly at Carrickacroman on 30 March 1875 indicates birth c. 1821, if the reported age by the informant Mary Casserly of Carrickacroman was accurate:
https://www.irishgenealogy.ie/files/civil/deaths_returns/deaths_1876/020584/7222271.pdfThe death of Margaret Casserly at Carrickacroman in 1 July 1887 indicates birth c. 1837, if the reported age by the informant James Casserly of Carrickacroman (stated as her son) was accurate:
https://www.irishgenealogy.ie/files/civil/deaths_returns/deaths_1887/06204/4774480.pdfThe following is a possible candidate for that son James in the 1901 census ...
https://www.census.nationalarchives.ie/pages/1901/Cavan/Larah_South/Carrickacroman/1048370/... and his marriage to Mary Brady in 1893:
https://www.irishgenealogy.ie/files/civil/marriage_returns/marriages_1893/10617/5868100.pdfA search of Griffith's Valuation for the townland of Carrickacroman (local print date of 1857) shows a Thomas Casserly leasing a house, offices and just over 17 acres of land.
https://www.askaboutireland.ie/griffith-valuation/index.xml?action=placeSearch