hi Brian, looking over the family in Drouin, they have children marrying in Warwick (St-Médard) up to 1874 where they are listed as residents of Warwick. On 21 June 1889 their son George Naud marries, again in Warwick, with his parents being recorded as residents of ''Barton, États Unis''. This is the last mention I find of her or her husband in this province.
I just checked the records for Warwick for 1906, she is not among those buried there that year.
I tracked the family geographically per baptisms of children etc, they marry in St-Pierre-les-Becquets, then have baptisms in St-Pierre-les-Becquets, St-Stanislas, one in Ste-Geneviève-de-Batiscan, and St-Tite. All of which are on north shore of St-Lawrence, the last such on Nov 1860. https://www.genealogiequebec.com/fr/LAFRANCE/carte/1105 map IGD (free access)
The marriages of the children start in 1871, and except for the last one in 1889 the couple is living in Warwick. Which is on south side of St-Lawrence.
Have you found them on census records anywhere?