This is very confusing.I found Alexander Surprenant age 35,single, blacksmith, living in Chazy on the 1880 census.
I also found, living in Beekmantown on the 1880 census:
Abram Fesette 54
Marceline, 50 wife
Peter, 28, son
Julia, 26, daughter
Sarah, 26, daughter
Isaac, 52, brother
So it appears Alexander and Julia were both single in 1880.
Also, in your post, the first three children have surnames of Fesette.Should they not be Surprenants?You also show Ross born in 1879, when Alexander and Julia were single and living in different towns.
I was able to sort some of it out on the 1900 census:
Chazy, Clinton County, NY
Alex Supernault, born Oct 1853 age 46, born NY
Julia, wife, born July 1853, age 46, born NY
Eva, daughter,born Oct 1883, age 16, born NY
Della, daughter,born Dec 1885, age 14 born NY
Ross, son, born Sept 1888, age 11, born NY
Ana, daughter, born Jan 1890, age 9, born NY
Emma, daughter, born June 1892, age 7, born NY
Lucy, daughter, born Aug 1895, age, 4, born NY
Leo, son, born Feb 1898, age 2, born NY
Abram Fessette, father-in-law, born Nov 1822, age 77, born Canada
Marceline, mother-in-law, born April 1830, age 69, 5 children, 5 living, born Canada
Hope this helps sort things out a little.
Bill St. George