I found the marriage you mentioned in the Drouin Collection at Ancestry and here are the basics (my French isn't very good so please bear with me):
Québec (St-Jean-Baptiste)
On 28 Apr 1919, Pierre Louis Joseph Marois, son of Pierre Marois and his wife Imelda Trudel married Marie Edwidge Cote, daughter of Joseph Cote and Laura Langlois.
Here's a possible marriage for Joseph and Laura:
Portneuf (Notre-Dame-des-Sept-Douleurs)
On 6 Feb 1885, Joseph Cote, son of Michel Cote and Agnes Gignac married Marie Laura Langlois, daughter of Felix Langlois and Elizabeth Piche.
Here's a possible marriage for Michel and Agnes:
Neuville
3 Oct 1854, Michel Cote, son of Germain Cote and Margarite Lortie married Agnesse Gignac, daughter of Edward Gignac and Anastasie M? (I can't make out her surname but it starts with a "M").
Here's a possible marriage for Felix and Elizabeth:
Cap-Santé
On 17 Jul 1849, Felix Langlois, son of Joseph Langlois and Genevieve Marcotte married Elizabeth Piche, daughter of Pierre Piche and Josephte Giroulx.
Here's a possible marriage for Pierre and Imelda:
L'Ancienne-Lorette Notre-Dame-de-L'Annonciation
On 10 Jan 1893, Pierre Marois, son of Canut Marois and Anastasie Meunier married Marie Imelda Trudel, daughter of Louis Trudel and Emilie Gauvin.
Here's a possible marriage for Canut and Anastasie:
St-Augustin-de-Desmaures
On 6 Jul 1867, Canut Marois married Anastasie Meunier.
I couldn't make out much of the details because the image was hard to read.
I found a baptism for Marie Edwidge/Hedwidge Cote at Québec (St-Jean-Baptiste) which occurred on 2 Mar 1891. In the margin it has Edwidge and in the body of the entry it has Hedwidge. Parents were Joseph Cote and Laura Langlois. The godparents were Real Bertrand and Rebecca Langlois.
There were two other entries for similar names (M Edwige Cote and Marie Edwige Laura Cote) in 1891 and 1905 but the parents listed were different so they weren't duplicate entries.
There were a lot more entries listed so you may want to consider taking out a two week trial of Ancestry.ca to go through the Drouin Collection for more information and double-check my "translations".
The family in in St. Jean Ward, Quebec, Quebec on the 1891 census. Here are links to the images at Library and Archives Canada (There are two pages per image. Joseph is the last entry on the bottom page of the first link and the rest of the family is at the top of the second link):
http://www.rootschat.com/links/0655/http://www.rootschat.com/links/0654/If you would like to search for some of the other names mentioned, the 1881 and 1891 Canada census are searchable by name and have images at Library and Archives Canada. Here's a link:
http://www.collectionscanada.gc.ca/census/index-e.htmlJacquie