John Donohoe was a son of Jeremiah Donohoe of Letter
Mary Burke was a daughter of John Burke and Mary Hayes of Maulatrahane

John Burke of Letter and Mary Burke of Maulatrahane married on 10 February 1872 in the Catholic Parish of Kilmacabea, West Cork.  The marriage witnesses were Jerh Donohoe and John Burke.

Children born in Letter and baptised in the Catholic Parish of Castlehaven & Myross were:-

Johanna Donohoe, 6 Dec 1874.  Sponsors: Tom Burke, Mary Donohue

Mary Donohoe, 1 Apr 1876.  Sponsors: Michael Burke, Mary Burke

Michael Donohoe, 1 Oct 1877.  Sponsors: Denis Burke, Mary Coakley.  married Bridget Hegarty

It appears the family moved to Ballaghadown North, Caheragh and had further family

Children born in Ballaghadown North and baptised in Caharagh Parish were:-

Margaret Donoghue, c. 1881

Bridget Donoghue, 24 May 1886

Census 1901:
http://www.census.nationalarchives.ie/pages/1901/Cork/Killeenleigh/Ballaghadown_North/1154533/

Census 1911:
Clearly the Enumerator completed the census form as the writing matches his signature.  One has to wonder if he visited the house at all?  Michael Donoghue and Bridget Hegarty are the parents of the two children on the census link below.  However the Form has the name of the Head of the Family as John.  Then his father's name is given as Michael. A bit of a mix up it seems.
http://www.census.nationalarchives.ie/pages/1911/Cork/Killeenleagh/Ballaghadown_North/440604/
 

Death:
Mary Donoghue died at Ballaghadown North, Caheragh on 26 May 1918.  From her death record she was married, aged 75 years, a farmer's wife.  Present at her death and the Informant to the Registrar was John Donoghue, widower, Ballaghadown North.