My 3x great grandparents are James Creagan (Creegan/Cregan) and Catherine Heaney (Hany/Haney/Heeney) - already you can see the research nightmare beginning. They were both born in Ireland, James around 1830 and Catherine around 1836, and married in London on 3 August 1857 (that certificate I have tracked down on ancestry.com). By 1858 their first daughter Margaret is born in Bacchus Marsh, Victoria, Australia (I can't find the birth record at all), but the next few children James, William, Mary and Catherine are all easy to find, with detailed birth certificates giving all sorts of consistent information.
After this the going gets tougher. An older relative of mine Geoff, researching the family pre-internet days, has James dying in New Zealand about 1867, another daughter Georgina being born on 4 October 1868 in Addison's Flat, Buller, and Catherine Heaney dying on 8 February 1925 in Westport. Geoff's work is really detailed and accurate (I am spending most of my time simply verifying his research), and I know that Georgina (Creagan, Stack then Gibson) really exists and was born in New Zealand, but I can't verify any of the details in this paragraph. No birth record for Georgina, no death records for Catherine Heaney or James Creagan, and this is searching both Australia and New Zealand sources.
When I ask questions here, rootschat members are brilliant at finding sources I never knew existed, and filling in details above and beyond the initial question (I always learn a lot about how to research), but these people really are elusive. I assume that my relative Geoff was also fooled by James Creagan's death, but he is really specific about the other information, giving dates and places, and I can't find sources at all. So my questions are, what sources can be found for Georgina's birth date, Catherine's death date, and what happened to James?