Robert, Found this on Ennis Baptisms Name Father Mother DateLeaden Ellon Martin Mary Molony 24/11/1841 While the surname is Leaden not Leader, if you look at Ellon rather than Ellen, it's possible the transcriber got both wrong. I can't see a Martin Leaden in Griffiths Valuation. So it could be a sister to Catherine. Have you looked for any other Leader arrivals in SA? I estimate Martin Leader to be born around 1810, so I doubt you would find him in 1825 Tithe Applotment lists as he would be barely 15. There looks to be a Thomas Leader in Drumcliff who may be his father but this is purely speculation. Perhaps significantly there are only 111 occurrences of the Leader surname in all of 1901 census, and only one who gives birthplace as Clare. I'm not sure if the shipping papers to SA are available. I believe the bulk of them were lost in a flood. Check with SA Archives of SA Society of Genealogists if there may be something there, or perhaps on Irish Orphans to SA. Unfortunately too, Clare records are not on the IFHF website. Sorry I haven't helped much. Peter in Sydney