Your great-grandmother must have been Leona Anna Plourde, the fifth child of Thomas Plourde and Marie Ann Martin. There were at least 8 children in her family. Her father, Thomas, was the 13th child of 17 born to Louis Plourde and Marcelline Gagnon. The reason I know is because Louis is my great-great-grandfather. Their 6th child, Germain, is my great-grandfather. I used to go to his farm on Plourde road on Flat Mountain when I was a young boy. My great-grandmother Sophie Chasse Plourde died in 1947 at the age of 96.