Margaret Cullety and Daniel Brown

All i know is Margaret nee Cullety was married to a Daniel Brown lived in Akaroa New Zealand had twins 9th August 1867 named Margaret and Ellen.
Where margaret and Daniel came from??... where they married not known??.. the name Cullety was fist seen on Margaret's daughters B/certificates,then all other certificates have the name Collett ...so not sure which spelling is the right one?....
New updates.........marriage certificate has Daniel and Margaret marring 1856 England,father Tho Brown and Dan culety....
Daniel was a sailor on the HMS Pearl.....when Daniel and Margaret moved to NZ in 1865 on the ...SS Zealandier....with three sons.
D,Brown b?.....John b/1863...Thomas b/1864.......then in New Zealand had another son Edward b/1865.....then the twins Margaret and Ellen b/1867.
Daniel died 1869....