Mcmeekan Robert of County Down Married Eliza Jane Withers from Donaghadee

my name is rosemaree gilmour, great grand daughter of robert& eliza jane mcmeekan. eliza came from donaghadee county down& robarrived at lyttelton near christchurch on the "arlington" in 1863 &married robert. they farmed at springston,near leeston and my grandfather was one of his sons. i would like more information about robert and eliza, especially their parents and where robert lived in county down,and what was his occupation. i have robert's death certificate but it does not give the relevant information i require. can anyone help me please?