Thank you all for your suggestions.
Trish, is that 1848 headstone you have for John Hendrie in Australia? The date of death I have for John William Henry is 20 July 1849, Riversdale. So the marriage though similar is robably a differnt couple.
I have only really just started actively searching this family myself now and those children listed are from other trees, and might not be accurate. I may have made the list several years ago (before I DNA tested) when I was looking to extend the family of my 3x gt grandfather Bryce Henry born c1802. By using the name Bryce as a marker I reached the following family.
Family of Brice Henry (1773-1852) and Mary Nelson (1772-1850)
James Henry b Jun 1798 d 1849 m Mary Nelson
Agnes Henry b c1801 m R Allen
* Bryce Henry b c1802 d 1879 m Eliza Ewing
Revd John Henry b 1807 d 1885 m Eliza Porter
Nelson Henry b c1810 d 1881 m Margaret Mulligan
* Mary Henry b c1813 m James McIlroy
Thomas Henry b c 1815 d 1901 m Mary Jane Kirkpatrick
* Isaac Henry b c 1817 d 1884 m Mary Mulligan
Brice Henry of Shanrod Co Down also had a brother John Henry of Shanrod who married an Agnes Nelson, so I think the two children of John William Henry, John Nelson Henry and Bryce neslon Henry are named after them.
Regarding the frist child, there are trees who say Agnes Clara Henry, who married in 1840, as born in Kirkoswald on 29 Mar 1824. In his letter back to Ireland, John William refers to her as his oldest daughter ( though not by name) and that she was married to an Edward Spenks (Spinks).
