Lovelace Nicholas became known internationally as an activist when, in 1979, she petitioned the United Nations over the treatment of aboriginal women and children in Canada by the government, in the case known as "Sandra Lovelace v. Canada" (1977–1981). Among the policies she criticized was revoking the status of a First Nations woman if she married a non-aboriginal man, and denying status to their children. As noted, this had numerous effect, including denying such women equal access to reserve land. It imposed a patriarchal model of identity, depriving married women of their independent rights and status. In addition, as many of the First Nations had matrilineal systems, in which children belonged to the mother's people, the law deprived the children of such marriages of their traditional First Nations identity.