I have been researching Loiselle genealogy for years and would love to be able to connect your descendants of Alfred into my larger family tree.
I don't have anything to confirm your theories that Alfred Loiselle in 1881 census is same as 1891 census. But neither have I found any other evidence of Alfred in 1881 Census.
I only have one Antoine Loiselle married to any Charlotte (in my research so far). Here are all the sources of the marriage information for Charlotte Jared. Alfred's brother, Ulderic ended up in in Providence, RI.
1.Antoine7 Loiselle(Jean-Baptiste6 Loiselle-Sinotte, Toussaint5 Loiselle, Joseph4 Loisel, Joseph3 Loiselle, Louis2 Loisel/Loysel, Louis1) was born October 23, 1811 in Saint-Marc-sur-Richelieu, QC (Source: Jacques Hebert, Saint-Marc-sur-Richelieu Research. BAPTÊME LOISEL ANTOINE in SAINT-MARC-SUR-RICHELIEU father LOISEL JEAN BAPTISTE mother DÉMARAIS FRANÇOISE born 10/23/1811 bapt 10/24/1811 year 1811 cure ROBITAILLE PIERRE).He married Charlotte Jared October 08, 1833 in St-Jean-Bte, QC (Source: (1) Genealogies des Principals familles du Richelieu, Vol II, Fr Georges de Fordy, published 1927. Listed as Antoine m. Charlotte Tetreau, (2) Marriages de St-Charles (1741-1967), St-Hilaire (1799-1967), Jean-Baptiste (1797-1967), Otterburn Park (1960-1967). LOYSELLE Antoine - Chambley (JB & Frse Desmaraise) St-Chs m. JARED Charlotte (Louise & Therese Blanchard)), daughter of Louis Jared and Therese Blanchard.She was born Bef. 1817 in QC.
More About Antoine Loiselle: Residence: 1833, Chambly, QC (Source: per marriage, of Chambly but born in St. Charles)
Children of Antoine Loiselle and Charlotte Jared are: 2. i. Alfred8 Loiselle, b. April 11, 1834, St. Charles, S-Hycn, QC; d. Bef. 1881, < QC >. ii. Adelaide Loiselle, b. June 29, 1835, St. Charles, S-Hycn, QC (Source: IGI.).