Hi I found an Anna Kilmartin b. 14 June 1884 to a William Kilmartyn and Brigida Reilly, christened on 17th June 1884 sponsors were Jacobus Kivlahan and Margarita Gillan. Also a William Jacobus kilmartyn b. 26.9.1885 to William Kilmartyn and Elizabetha McDonnell christened on 27.9.1885 sponsors were Michael kilmartyn and B. Gillin. They are the only two births I see in Rosses Upper/Lower/Point between May 1880 and July 1896. (spellings as found) Does this help? I know its a bit later than your dates.