Your information seems to derive from the on-line version of the 1881 census of Glenelg Parish, Northumberland Co., New Brunswick in which Hugh McDonald (b. ca. 1836) has a wife, Marrion (ca. 1845) and children: William (10), John (9), Hugh (8), Robert (5) and Margret (1.)
Examining an image of the original at the Archives Canada we site shows 'Marrion' to be difficult to read, but more like something such as 'Meri(on'?
In Glenelg Parish, in 1871, Hugh Mcdonald is b. ca. 1839, and his wife is Mariah (ca. 1845.) Their son is J. William age 6 months. With them was Roderick Mcdonald (ca. 1796) possibly Hugh's father.
In Glenelg Parish in 1851 Hugh McDonald (b. ca. 1837) was the son of William (ca. 1802) and Margaret (ca. 1812) McDonald. Roderick (ca. 1795) and his wife, Sarah (ca. 1804) McDonald live very nearby and was likely Hugh's uncle. Both Roderick and William were born in NB, so are not likely one of the more recently arrived McDonald's. The family is transcribed as:
McDonald William M Head 49 Scotch Farmer (prop) Birth
McDonald Margaret F Wife 39 Scotch Birth
McDonald Alexander M Son 23 Scotch Birth
McDonald John M Son 21 Scotch Birth
McDonald William M Son 19 Scotch Birth
McDonald Robert M Son 17 Scotch Birth
McDonald Hugh M Son 14 Scotch Birth
McDonald Jane F Daughter 11 Scotch Birth
McDonald Anne F Daughter 8 Scotch Birth
McDonald Susanna F Daughter 6 Scotch Birth
McDonald Ronald M Son 3 Scotch Birth
McDonald Mary F Daughter 3 m Scotch
The confusion about Marion-Maria is resolved by an entry in the 15SEP1866 edition of the Chatham, "The Gleaner and Northumberland Schediasma", abstracted as:
"m. Chatham (North. Co.) 10th inst., by Rev. Frederick Home, Hugh McDONALD / Miss Marion Maria McDONALD both of Glenelg"
There was, in 1851, in Glenelg Parish, a daughter of John (ca. 1814) and Margaret (Russell) (ca. 1823) McDonald given in transcription as 'Karin' (b. ca. 1846.) Looking at an image of the original, I suspect that the name was 'Marin'. With them was my severl-times great aunt, Jane McKinnon. This suggests to me the families of Angus McDonald and Alexander McDonald, slightly nebulous persons, but bot apparently Loyalists and bot apparently associated with the Queen's Rangers. It is not something I have gone into too deeply, only being peripherally interested in establishing Jane McKinnon's connection. It seems that she and Margaret (Russell) McDonald were 1st cousins through their Forsyth mothers. In any case, I suspect that Marion Maria McDonald was the 'Karin' in 1851 and checking the 1861 census for Glenelg Parish might be of help. Other wise, I cannot find a female McDonald borne between 1844-6 who might have been Marion. Also, John McDonald and Margaret Russell were married at Point Aux Car 6JAN1840, and that is where Marion is said to have been born.
A birth record exists for Hugh A. McDonald, s/o Hugh and Marion M. (McDonald) McDonald giving him as born Black River, Northumberland Co., NB 26OCT1870. This contradicts both the 1871 and 1881 censuses and, I believe, is incorrect. It gives both his parents as b. Black River Bridge which is why I suspect the families of Alexander and Angus McDonald in particular. It also states that his mother had only 5 children. This also is incorrect as another birth record states that Hugh and Marion had a daughter, Linda Mabel McDonald b. Black River, Northumberland Co., NB 12OCT1885. In addition to the 5 children in 1881, she makes at least 6. Her birth record gives her father as b. Black River (slightly distinct from Black River Bridge, but not so as you would really notice) and her mother as born at Point aux Car. Hugh, Alice and Alex McDonald, and close by, Roderick and Alex McDonald, had grants (according to cadastral maps) downstream on Black River, but below the place, Black River. A bit further downstream, and towards to Miramichi is the place, Black River Bridge. Alice McDonald received her grant in 1882, Hugh in 1879 and Alex in 1879 also. This appears to be a subdivision of a larger, likely inherited, lot. The Roderick and Alexander lots, side by side, each 200 acres, appear to have been granted at the same time. Roderick and Alexander, Jr. were each granted one-half of 400 acres in Glenelg Parish 11DEC1812. This suggests that they were sons of Alexander MacDonald, the Loyalist, although 'Jr.' does not always mean a father-son relationship especially in a place were there were 180 McDonald's in 1851, half of them likely named Alexander. Even so, combined with the location, the idea is suggestive. On the other hand, the New Brunswick Genealogical Society web site, "First Families", especially at:
http://www.nbgs.ca/firstfamilies/FAMILY-McA-McY-2006.pdfhas:
MCDONALD: Alexander McDonald b. 1775 at Assynt, Scotland, died 1843: came from Assynt to Cape Breton in 1803: married Grace MacAskill b. 1781, d. 1874: came to NB: settled at Black River, Glenelg Parish, Northumberland County:
Children:
1) Kenneth McDonald b. 1804, d. unmarried 1837:
2) Hugh McDonald b. 1808, d. unmarried 1873:
3) Isabella McDonald born 1810, d. 1893, married 1848 Roderick McKenzie of Tabusintac, Alnwick Parish, b. 1808, d. 1893: had five children:
4) Anne McDonald born 1813, d. 1896, m. 1834 William McKnight b. 1804, died 1865: they had ten children:
5) Margaret McDonald b. 1815, d. 1900, married William Godfrey b. 1825, died
1904: they had no issue:
6) Mary McDonald born 1821, died 1885, m. Fred or Roderick Robinson:
7) Jessie McDonald b. 1823, d. unmarried 1912:
8) Annabel McDonald:
9) John McDonald m. 1842 Elspeth R. Jardine b. c1820, d. 1906.
Sources: MC1/McLean #3, 1 page: see also MC80/2689 Miramichi Branch of the NBGS, Some first families of the Miramichi, 1 page.
which suggests more than one McDonald family in a fairly small area.
Hugh and Marion are also in Glenelg Parish in 1891 with children: William James, John Alexander, Hugh Allen, Robert Clifford, Margaret Elizabeth and Linda Mable. They were all b. NB, and their parents were also b. NB, suggesting Loyalist McDonald's rather than arrivals after 1783.
They were in Glenelg Parish in 1901. Birth-dates in 1901 are often unreliable, for various reasons, and I use them only if there is not anything better. Hugh Allan's birth-date of 14JAN1874 bears no resemblance to any other birth-date given except to support that he was likely born after 1870, probably in 1873.
By 1911, Hugh, Sr. has died. Hugh A. (JAN1873, a more likely date) and Myra (OCT1879) have, next door, a family, Frederick McDonald (AUG1876) and his wife, Margaret (FEB1880) and children; and with them an aunt, Marion McDonald (OCT1847.) Frederick James McDonald m. Margaret Elizabeth McDonald, so Marion could be aunt to either. Margaret appears to be Marion's daughter, so Marion is more likely Frederick J. McDonald's aunt. This is supported by their marriage registration which makes Margaret the d/o Hugh and Marion. The maiden name of Frederick's mother is hard to read, but it looks like 'Beraphill?'.
In Glenelg Parish in 1901 Frederick's parents are William (14JUN1854) and Isabella (21JUN1856.) Children are: Alexander, Donald, William G., Archibald, Campbell and Elizabeth. When Archibald got married, his mother's maiden name was Campbell. William McDonald m. Black River 16OCT1874 Isabella Campbell. If William was b. 1854, then he can only be William Macdonald b. ca. 1855, s/o John (b. ca. 1830) and 'Susana' (Susanna McLean, m. 11OCT1853) (b. ca. 1834) McDonald. They lived two households away from Hugh and Maria McDonald in the 1871 census. I think John McDonald b. ca. 1830 was John b. ca. 1830 in 1851, s/o William and Margaret and Hugh's older brother. Thus Marion was not so much Frederick James MacDonald's aunt in 1911, as his great aunt by marriage.
HUGH McDONALD (s/o William and Margaret McDonald) b. Black River Bridge, Glenelg Parish, Northumberland Co., NB 9APR1839 (ca. 1836-9), m. Chatham, Chatham Parish, Northumberland Co., NB by the Rev. Frederick Home 10SEP1866 MARION MARIA McDONALD (b. Glenelg Parish, Northumberland Co., NB 12OCT1846 (ca. 1845, OCT1847 in 1911.)
Children:
1. WILLIAM JAMES (J. WILLIAM) McDONALD b. ca. 1870-1
2. JOHN ALEXANDER McDONALD b. 20OCT1872 (ca. 1872), m. AGNES _____ (b. 17JUL1876)
3. HUGH ALLAN McDONALD b. Black River, Glenelg Parish, Northumberland Co., NB ca. 1873 (26OCT1870 in birth registration; ca. 1873 in 1881 and 1891, 14JAN1874 in 1901), m. Black River Bridge, Glenelg Parish, Northumberland Co., NB 6SEP1899 MYRA TAYLOR (b. Lower Napan, Glenelg Parish, Northumberland Co., NB 1DEC1878 (ca. 1877)), d/o John R. and Elizabeth (McDonald) Taylor
4. ROBERT CLIFFORD McDONALD b. Glenelg Parish, Northumberland Co., NB 15AUG1875 (ca. 1855-6)
5. MARGARET (MAGGIE) ELIZABETH McDONALD b. ca. 1880, m. Northumberland Co., NB 3MAR1897 FREDERICK JAMES McDONALD (b. Black River, Glenelg Parish, Northumberland Co., NB AUG1876), s/o William and Isabella (Campbell) McDonald
6. LINDA MABEL McDONALD b. Black River, Glenelg Parish, Northumberland Co., NB 12OCT1885 (ca. 1886)
Thomas