Were you a Canadian citizen when the child was born?
If yes, then the child has the right to citizenship and you can apply for a citizenship card for the child, see http://www.cic.gc.ca/english/citizenship/proof.asp
If no, then you could sponsor the child for PR but only if you are planning on moving to Canada with the child when it gets the PR. You could also leave it until the child is grown. A child is considered dependent and can be sponsored for PR by a parent as long as the child is under 22 and not married or if it is older than 22 and a full time student since before that age and therefore financially dependent.