Dollard Family Genealogy Forum
As far as I've found Adam Dollard Des Ormeaux wasn't married, had no known descendants and I'm not aware of any brothers. He's still considered a hero in Quebec and they have a provincial holiday annually in his honor so it seems likely that if anyone there was related to him in any way they would have spoken up years ago. When you consider that your Marie Delard had Irish ancestors and the Delard surname is apparently even more unusual than Dollard I certainly wouldn't rule out the possibility that her surname was an alternative spelling for some other surname, possibly Dollard. But it looks like you'll have to dig a little more into her father's family to find out.