I am a descendant of Thomas Laroche by his son Alfred who stayed in Québec after Thomas moved to the USA in 1902.
What we know about this story is that Thomas and Célénire adopted a baby before they left. The name we have is: Yvonne Roberge.
There are three possibilities:
l. She was the child that Celenire had with Damasse Grenier, her first husband.
2. Celenire s sister Caroline married a man called Pierre Roberge and had 2 children: Lea Roberge and Yvonne Roberge.
3. She is a child that Thomas and Celenire adopted from the Black Lake Orphanage(which is a little town near Halifax, where they were living).
If it is possible for you maybe you could send us the date of birth of Yvonne. We could see if your infomations you have matches with ours.
Have a nice day!