Hello
I’ve had a look in my files as I’ve been doing some of the same mapping on the O’Neills in this area.
I found my notes on Thomas O’Neill and Isabella Campbell. I couldn’t get back any further with them, but they had another possible child in 1827
Ellen O’Neill baptised 24 Feb 1827, sponsors Owen, Margaret McClean. Clonoe, Father Thomas, mother Elz Campbell.
Out of interest do you know if Isabella Campbell has a sister called Eleanor?