I have found some listings online giving Marie-Marguerite or Marie-Madeleine Hervieux, daughter of Paul Hervieux and Marguerite Ethier as the wife of Joseph Gerlais(e)(later known as Desjarlais). It is in fact Marie-Josephte Hervieux, daughter of Paul Hervieux and Marguerite Ethier, who married Joseph Jarlais (Gerlais) Dit St-Amand on May 29, 1752 at St-Antoine-de-Lavaltrie, Berthier, Québec. This information can be confirmed through the PRDH database and the parish register of St-Antoine-de-Lavaltrie. Marie-Josephte was born to Paul Hervieux, Dit Lesperance, and Marguerite Ethier, in 1732 (baptised March 20, 1732 in St-Sulpice, L'Assomption, Québec).
Marie-Marguerite, sister of Marie-Josephte, married Jean-Baptiste DAUNAIS (aka Daunay or Donais) on 13 May 1748 in St-Joseph-de-Lanoraie, Berthier. Source: Marriage record. Marie-Marguerite was baptised June 11, 1730 in St-Joseph-de-Lanoraie, Berthier.
I do not find a Madeleine in the family other than sometimes I see Marguerite-Madeleine Hervieux as the wife of Jean-Baptiste Daunay.
Also I find Marguerite and Josephte (Josette) used as names of the same individual (e.g. also called...). However, Marguerite was born in 1730 and died in 1750, which is before 1752 when her sister Josephte (born in 1732)was married to Joseph Desjarlais.