Matt99, unfortunately citizenship by descent is now limited to the first generation born abroad, so your grandmother would be the only possible recipient. However, you need to find out when your great-grandfather immigrated and became a Canadian citizen because citizenship by descent only works if the parent is a Canadian citizen when the child is born. So since your grandmother was born in 1940, before the Canadian Citizenship Act was first enacted in 1947, there is a strong possibility that, unless he became a citizen in 1947 because of the Act and can prove that he would been considered a Canadian citizen (i.e. a British subject born, naturalized, or domiciled in Canada prior to 1947) when she was born in 1940, your grandmother is probably not a citizen by descent.