It depends on how your daughter obtained her Canadian citizenship. If she is a naturalized Canadian (she immigrated to Canada, received permanent resident status, and then successfully applied for citizenship) or if she was born in Canada and therefore is also a Canadian citizen, her son can receive Canadian citizenship by descent from her. However, if she was born abroad to a Canadian parent (she receieved her citizenship by descent) then she cannot pass on her citizenship to any child of hers born outside Canada. (There is an exception for members of the Canadian military.)
