I have had a look at your other listing re Samuel Hart & Rebecca Kelly.
You say Samuel was born near Belfast in 1815, but married in Clare Presbyterian Church in Armagh.
If you listed the children in order of age, there is a chance Samuel's father was named James.
I could not find any Harts or Kellys in Co. Cavan, in the Tithe Applotment inddex, but the index is not always accurate.
There were c. 40 Harts listed for Armagh.
I am not sure of the location of this church, as I live in Co. Down.
I will have a look at this again, and try to post the list of Harts later. It may be tomorrow before I get time.
There were too many Kelly names to list.