I now know that Emelie Latourelle and Amelie Pontbriand are 2 different people. Here is the marriage info:
Olivier Giasson(age 25) son of Olivier Giasson & Flavie Rivard married at St. Joseph du Corbeau on Feb. 28, 1870 Armenie Latourelle(age 16), dau. of Francois Latourelle & Julienne Rivet
OLIVIER JEANNOTTE (ANSELM4 GENNETTE, FLORENT3 GIASSON, JEAN2, JEAN BAPTISTE1) married AMELIE PONTBRIAND July 04, 1854 in St. Joseph du Corbeau, Coopersville, Champlain, New York
It would appear that there might at least 4 Oliviers. Anselm had 2 other brothers that came down from Canada with him, so it's possible. Olivier married to Flavie Rivard Olivier Jr. son of the above who married Emelie Latourelle Olivier who marrird Amelie Pontbriand in 1854 Olivier Jr. son of the above couple, born in 1859
Another possibility is that Flavie was Olivier Sr's first wife and she died young. Perhaps this is the case and there is confusion as to Olivier Jr's real mother. Let me know if you have this information or what your thoughts are about it.
I have Helen Durands ancestry 100% complete back to the 1600's. Do you have this info? If not, send me an e-mail and I'll send you what I have.
Also if you are interested, I can put you in contact with about a half a dozen other descendants of this family who are actively researching themselves. It's good for acuracy sake, to compare notes and exchange information with each other. Just let me know.