Re: Edward and Elizabeth Howden from Ireland to N.Z.
I would not be surprised if Edward is brothers with my G-great Grandfather Alexander Howden, from Fermanangh, who came to NZ in1875 on the Waikato. He married his wife Sarah Jane Hyndman in Christchurch before heading north. I have just heard from a descendent of his brother Robert, who came over with his wife (also a Taylor) in 1876 on the Conflict, perhaps with your Howdens.
Alexander and Robert share the parents James Howden and Rebecca Taylor.