HI Patty. I can't believe you saw my message – and that you replied so quickly. No, I am not related to the family. My interest is in the history of blacks in the Montreal area in the 18th and 19th centuries. I published a book of stories about some of them in 2004: it's called Black Then: Blacks and Montreal, 1780s-1880s (McGill-Queen's University Press, 2004). In one of the stories, I wrote about the circumstances of William Thomson's death at Berthier.
Until today, I did not realize that Marguerite Eulalie had died in Woonsocket. I also wondered what had become of her sister, born in 1820 and baptised Eleonore. Do you know? I believe she later went by the name Adèle Thompson (which might account for Eulalie naming one of her daughters Adèle). in 1874, Adèle, then said to be from Sorel, directly across the St Lawrence River from Berthier, married a Sorel man named Benjamin Landry at Berthier. They lived at Sorel where she died in the General Hospital on 17 March 1891.
Anyway, nuff said. I would love to see your picture of Eulalie. There are so few pictures of Quebec blacks of that time.