John Mahony was a son of George Mahony and Johanna Daly.
Kate Sullivan was a daughter of Daniel Sullivan

John Mahony, farmer of Derreenacrinnig and Kate Sullivan of Gortnacowly married in the Bride's house on 5 February 1874.  The Witnesses were Daniel Sullivan and John Sullivan. We note at the time of the marriage from the marriage entry that John's father, George, was deceased.

Children born in Derreenacrinnig and baptised on dates on Baptismal Register:

Johanna Mahony, 22 Jan 1875.  Sponsors: Daniel Leary, Margaret Sullivan

Ellen Mahony, 18 Mar 1876.  Sponsors: Lin Sullivan, John Mahony

Honora Mahony, 30 Dec 1877.  Sponsors: George Mahony, Ellen Mahony

Jeremiah Mahony, record not to hand

Kate Mahony, 23 May 1882 from Civil Birth Register

Census 1901:
http://www.census.nationalarchives.ie/pages/1901/Cork/Dromdaleague_North/Derreenacrinnig_West/1153935/

Death:
John Mahony died at Derreenacrinnig on 4 June 1901.  From his death record he was married, aged 63 years, a farmer.  Present at his death and the Informant of it to the Civil Registrar was Hannah Mahony, his daughter of Derreenacrinnig.

Census 1911:
http://www.census.nationalarchives.ie/pages/1911/Cork/Dromdaleague_North/Derreenacrinnig_West/440134/