You can expect the spelling of the surname to vary a bit in the records. That was very common in Ireland. This may be your family in the 1901 census in Ballyportery South:
http://www.census.nationalarchives.ie/pages/1901/Antrim/Killagan/Ballyp…
They aren?t there in the 1911 census which probably fits the dates you have. However Sarah (junior) seems to have moved to Ballyportery North:
http://www.census.nationalarchives.ie/pages/1911/Antrim/Killagan/Ballyp…
Here are some probate abstracts (summaries) which appear to relate to the family. The full files are in PRONI in Belfast.
Probate of the Will of Sarah McCluskey late of Ballyportery, Co. Antrim, widow, who died 21 March 1911 granted at Belfast 27 August 1920 to Alexander Richmond, Farmer. Effects: ?216 17s 6d.
McCloskey Sarah of Ballyportery county Antrim spinster died 9 July 1934 Probate Belfast 8 January to James Ward farmer. Effects ?35.
McCloskey William of Ballyportery Culcrum P.O. county Antrim farmer died 23 November 1943 Probate Belfast 3 April to Daniel McKay and James Currie farmers. Effects ?213 13s. 7d.
Griffiths Valuation for 1861 lists James McCluskey in Ballyportery South. He farmed plot 1 which was a farmhouse and just over 13 acres of land. That?s on the north side of the modern Ballyportery Rd between Cloughmills and Loughguile village.