Helen, I am not connected, but I strongly suspect that your "John" Gordon was actually Cormac Gordon. I draw this inference from:
* the following extract taken from the VRI (which is in Latin); and
*your own list of children, one of whom is named as 'Cormac' (a fairly uncommon name in Roscommon).
+++++++++++++++++++++++++++++++++++++
GORDON, Brigidam Christening
Gender: Female
Christening Date: 12 Jul 1817 Recorded in: Laughlin, Roscommon, Ireland
Collection: Roman Catholic
Father: Cormici GORDON
Mother: Annae HUNT
Source: FHL Film 989753 Dates: 1817 - 1826
++++++++++++++++++++++++++++++++++++++Also, Cormic may have had a brother, Martin, who married (possibly) the sister of Ann Hunt, ie, Elisabeth Hunt. As you can see, this couple lived in the same area, and had their children about the same time.
++++++++++++++++++++++++++++++++++++++
GORDON, Annam Christening
Gender: Female
Christening Date: 18 Jun 1817 Recorded in: Laughlin, Roscommon, Ireland
Collection: Roman Catholic
Father: Martini GORDON
Mother: Elisabeth HUNT
Source: FHL Film 989753 Dates: 1817 - 1826
++++++++++++++++++++++++++++++++++++++
By the way, your e-mail address did not work.
brianfw@ozemail.com.au