In 1891, in Simonds Parish, Carleton Co., NB, Rosa Melvill was a widow age 45 years (b. ca. 1846.)
In 1881, in Simonds Parish, John Melvill was b. NB ca. 1842 and Rosella was b. NB ca. 1847. The children were b. NB, except for John (ca. 1871) b. US. This may be why, in 1871, the only Melvill in Carleton Co., NB is William Melvill (ca. 1835) with a wife, Ann (ca. 1860.) In Simonds Parish there was a George W. Melville (ca. 1843) and his wife, Ann (ca. 1845) and children.
An Ann Melville, wife of James Melville, d. Victoria, Peel Parish, Carleton Co., NB 11DEC1861 age 45 years.
A Mary Melville, wife of William Melville, d. Woodstock 27SEP1877 age 74. Her death was also noted in Charlotte Co., NB and apparently in Maine. William died at the home of his son, Arthur Melville, in Saint John, 17DEC1882 age 83 years. In 1851, in Dukes & Queens Wards, Saint John, Saint John Co., NB, William (ca. 1801) Melville was a caulker and Ann was b. ca. 1807. They did have a son, John, but he was b. ca. 1835 so was unlikely the same John. In the 1865 directory, William Melville (shoemaker) and Arthur W. Melville (printer) were in Woodstock. In 1867 George W. Melville was also a shoemaker, so likely William's son. By the 1871 directory G. W. Melville is postmaster as well as a shoemaker in Simonds Parish. Arthur W. (printer) is back in Saint John and William is not listed. In 1851, William and Ann's son, George, was b. ca. 1839.
This is contradicted by George W. Melville's death registration. It states that he was b. NB 31JAN1843 and was the s/o James and Mary (Smith) Melville. His father was b. Nova Scotia and his mother was b. NB. Again, if this is true, where were they in 1851?
According to the marriage record of Moses E. Melville, s/o John and Rosie (DeLong) Melville, his father was b. in Carleton Co. If this is so, I have yet to see his family there in the 1851 census. In 1891 George's father was b. NS but his mother was b. US.
From all of this I can only suspect that John Melville was likely related to George W. Melville, therefore a son of James and Mary (Smith) Melville. Perhaps James and William (the shoemaker) were the same person, and the Mary who d. 1877 was Mary Smith. If so, where was she in 1871? The problem is that she is listed as 'Milville' in Woodstock Parish in 1871 (age 67) with William (71.) Both are given as b. NB so, again, they do not seem to be George's parents.
I hope this is more helpful than confusing.