You do not seem to have received a reply to your query. A few notes that may be useful still.
Marie-Louise Morin wife of Guillaume Rousseau went by the given names of Louise or Luce or Marie in the marriage records of her children.
Guillaume was mentioned as Gaudiose in the marr. record of his Daughter Marie-anne to Cadrin.
I have in Quebec, found marr. records for only two sons of Guillaume and Marie-Lse:
Narcisse to Léocadie St-Ours, 4 Feb 1856 at St-Maurice and
F.X to Reine Mercier, 28 Aug 1838, St-Vallier
Death dates: are difficult to obtain ; no central registry for that period.
For marriage records, I suggest the BMS2000 database for your research. Here is a short guide.
BMS2000 basic instructions.
BMS2000 is a database of baptisms, marriages and deaths («S« stands for «sepulture» or «burials») records for the province of Quebec, a little from Ontario. The data were taken from parish or counties repertories. English and French versions of instructions are available. More marriages than B and D because B- and D repertories were produced for no more than 10 % of the Quebec parishes and few or none from the Montreal area. Given that the data are taken from repertories, one has to be aware that if the repertory was produced in 1980 and for which there has not been any update, the marriages for the post-1980 period are not available in BMS2000. To make up for it, we in Quebec use the marriage and death database of the Quebec Statistics Bureau or Statistics covering the period of 1926 to 1996. Now avail. on line. Register if you want to make research in Quebec. 25 free queries. Thereafter, you may deposit some funds. about 10 cents per query. No charge if you do not get the full details of the record. I suggest that you search with surnames of the couple only (no given names). If the surname of a partner has numerous variations, use the surname of the other partner and one or two given names (bride and groom). Rather easy to use. To search for a marriage: select: SPOUSES (in the upper right corner section) and type in only the surnames of the partners. Click on the applicable line to see marriage data. If you want the name of the married male children of a couple, from the parents’ marriage data, click on CLOSE (bottom right of the screen), select: GROOM's parents. A line with names will appear for each son. Click on each line one at a time to get details . To get the names of the married female children of a couple, go back to the line with the parents’ names (step 1), select: Bride's parents (because when the daughters of a couple get married, they are brides) .Again, click on every line to reveal the name of the daughters and their marriage data. This may sound complicated but it is not after a few attempts. Contact me if you need more info. I have no financial interest in BMS2000.
Unless a birth and death repertory have been prepared from the parishes registries, it is difficult to obtain the info.
The other option is with Ancestry.Com and you have to access Drouin's database for the Quebec parishes. I will try to find a more complete link name and will send it to you. What you do in fact is that you access the applicable church registry.