Dette, I have a feeling I replied to you on this topic some time ago, advising you that there appears to be a fundamental mix-up in the information you have on the Jeremiah McIvors.
I will again set out the details as they are in the Ardboe registers plus the inscription on a headstone this should clarify things for you, hopefully.
The Ardboe parish (Catholic) marriage register contains the following entry, partly in Latin:
25 Maii 1849. Jeremium McIver et Sara McIver. Testibus Jacobo et Maria McIver
(In English) 25 May 1849. Jeremiah McIver and Sarah McIver. Witnesses James and Mary McIver
The baptismal register contains the following baptisms:
15 March 1850 Nancy Ann of (blank) McIver and Sarah McIver. Sponsors: Hugh McIver and Margaret McEver. [Address] Mullaghwhitra (a townland in Ardboe parish)
16 December 1852 Joseph of Jeremiah McIver and Sara McIver. Sponsors: Patrick Mulvanagh and Hanagh McIver. [Address] Barracks (a hill in the townland of Drumaney in Ardboe parish)
2 November 1854 Mary of Jeremiah McEver and Sarah McEver. Sponsors: John and Mary McEver
5 September 1856 Patrick of Jeremy McEver and Sarah McEver. Sponsors: John Mallon and Sarah Muldoon
I would very much doubt that this Jeremiah McIver/McEver was the man who married Isabella Harbison in Ardboe in 1876 and had five children, namely Jeremiah (1877); James (1879); Hugh (1881); Anne (1883); John (1886?)
There is a headstone in Mullinahoe graveyard in Ardboe which has the following inscription:
Pray for the souls of Jeremiah McIvor, Ballymurphy, died 6th May 1900 aged 63. His wife Isabella died 7th April 1910 aged 67. His daughter Annie died 8th March 1909 aged 23. And his sons James died 27th April 1933 aged 54. Jeremiah died in USA April 1945. His daughter-in-law Mary McIvor died 1st Oct 1956 aged 57. And her husband John McIvor died 5th Feb 1983 aged 97. Hugh died in Glasgow April 1965 aged 76. McIvor
There is no baptismal entry for a Jeremiah McIver/McEver/McIvor in 1837 or around that date. However there are two baptismal entries for children of Jeremiah McIver and Anna McSloy:
27 September 1832 Mary of Jeremiagh McIver and Anna McSloy. Sponsors: Michael Brien and Mary McIver. [Address] Barracks (a hill in the townland of Drumaney in Ardboe parish)
4 March 1836 John of Jeremia McIver and Anna McSloy. Sponsors: Hugh Banigan and Sara Brien. [Address] Barracks (a hill in the townland of Drumaney in Ardboe parish)
Its my guess that the Jeremiah who died in 1900 belonged to this family. He may have been born in 1837/38, but for some reason his baptism was not registered; it is also possible that a mistake was made in the 1836 entry (John instead of Jeremiah).
I would also suggest that the Jeremiah who was married to Anna McSloy in the 1830s may have been the man who married Sarah McIver in 1849?