Essentially making a few guesses (although it fits together so well) I found a bit on Benjamin that might be useful giving some perspective as to event and places.
BENJAMIN HERRINGTON, b. ca. 1796, drowned in Mr. Sulis' ship yard, Courtenay Bay, Saint John 4NOV1856 age 60 years, m. 1st JAN1819 MARY GREENE; m. 2nd OCT1843 MARY ANN (MARIAN in death announcement) (KNIGHT) McCLELLAN (b. 5JUN1808 (ca. 1808), d. 27MAY1872 age 64 years; m. 1st David McLellan (b. ca. 1801, d. 12SEP1840)). d/o Joshua and Jane (Vernon) Knight.
Mary Herrington, wife of B. Herrington d. St. Andrews St. Saint John, Saint John Co., New Brunswick APR1833 age 31 years. I feel this was Benjamin's 1st wife and this was the same Benjamin named as one of the administrators of the estate of Joseph Harrington in 1827. They likely lived at Oak Point, Greenwich Parish, Kings Co., NB just up the River Saint John from the City of Saint John. Mary left 5 children when she died. Benjamin Herrington m. Saint John JAN1819 Mary Greene. Benjamin was of Kings Co. at the time and Mary lived in the city.
The Saint John, "New Brunswick Courier", 3AUG1839 had an item:
"Terrence LEONARD, one of the persons engaged in the barberous murder of Beranrd COYLE last week in Kings Co. and who subsequently absconded, was apprehended near the Salt Works at Eastport, Maine (whither he had gone by land) on Monday eve. by a peace officer from this city. Benjamin HERRINGTON brought him back in the steamer "Nova Scotia" on Tuesday. Mr. H. was readily aided in his endeavours to arrest the murderer by Mr. DREW, Deputy Sheriff and Mr. PIKE of Eastport."
This suggests that Benjamin was in some law enforcement capacity. He appears, so far, to have been a ship carpenter (i.e. worked on building ships as opposed to being a carpenter on a ship).
When Benjamin died, he left a widow and 7 children. At a guess, the 5 by his first marriage and then the twins by his 2nd marriage. It is clear, at least, that he remarried.(Note that Mary Ann Knight was herself a twin.)
When Marian/Mary Ann died of apoplexy, her funeral was from her son's residence near the intersection of Queen and Pitt streets in Saint John. She was the widow of the late Benj. Herrington. Her son, David McLellan, was listed three times in the 1871 directory as a lumber surveyor living in Indiantown near Portland & Main streets. Even so, I do not fin him in the 1871 census although portions of Portland Parish are included. I keep running into this problem that seems to affect, specifically, Indiantown when I seek my own relatives there in the 1871 census. I know they were there (as in the directory) and I see references to them being there in that census, but the government of Canada web site for that census does not have them. From this, I get the sense that Marian's older children by her 1st marriage may have stayed in Indiantown after her 2nd marriage. According to the Provincial Archives of NB web site, much of the 1861 census for Saint John Co. exists. They have the relevant films in Fredericton, but to get them by interlibrary loan who have to ask for the copies in Ottawa, Ontario with the National Archives of Canada (Library & Archives Canada), 395 Wellington Street, Ottawa, ON, K1A 0N3.
'Herrington' may be a preferred spelling. I assume John Herrington (b. ca. 1824) was Benjamin's son as he lived one or two households away in 1851 and he was John 'Herrington' in the 1871 census. He may have been the John Harrington, constable, living near the intersection of Wentworth & Queen. Perhaps he was the 'son' (stepson?) living near Pitt & Queen when Marian/Mary Ann died.
1. HARRIET H. HERRINGTON (eldest daughter), m. 30OCT1840 WILLIAM DENNIS.
2. ELIZABETH HERRINGTON (2nd daughter) b. ca. 1827, m. _____ KELLY, d. Cambridge (Boston), MA 15OCT1867.
3. ABIGAIL HERRINGTON (3rd daughter), m. Germain St. Baptist Church, Saint John JUN1849 THOMAS H. BRADSHAW.
4. JOHN HERRINGTON b. ca. 1824, m. MARIA _____ (b. ca. 1808 (?) (ca. 1825 in 1871)).
6. JANE VERNON HERRINGTON (twin) b. ca. 1844, m. Saint John 21DEC1866 CHARLES TUTTLE.
7. JAMES HERRINGTON (twin) b. ca. 1844.