Hello, I don't know if you have already found this info, but it seems that your Marie-Louise Papineau is a cousin to my Marie Francoise Papineau.They were also doubly cousins because their dads were brothers and their moms were sisters!Your M. Louise is the daughter of Pierre Papineau and Marie Louise Ouellet.(My M.-Francoise the daughter of Jean-Baptiste Papineau and Marie Angelique Ouellet(Angele for short). Pierre and J-B.'s parents were Pierre Papineau (Sr)and Marie Josephte Brignon dite Lapierre(Marr. 30 June 1739,Sault-au-Recollet(now in province of Quebec,Oka area) Next up the line were Samuel Papineau dit Lapierre and Marie Catherine Quevillon,(marr. 6 June 1704 Riviere-des-Prairies). Now the Ouellet girls' parents were Joseph Ouellet and Marie-Louise Rouleau,marr. 7 Fev 1745, St-Laurent Mtl.
So Louise Papineau(b. 19 Aug 1775 St-Martin de l'Ile Jesus(now Laval,Qc.) marr.19 Juil 1791,St-Martin, J.B. Giroux, , he was son of Joseph Giroux(son of Jos. & Charlotte Chorot or Choret) and M.Catherine Fortin(marr. 11 Feb. 1765 Sault-au-Recollet).They had at least the following children, Seraphin, Scholastique, J.B., Pierre, Francois. Seraphin Giroux married Marg. Lacasse 12 Dec 1856 St-Sauveur,Terrebonne,Qc.(I think their son Seraphin married a Louise Sarazin.I hope this helps. Good luck in your search.!