Good evening ma'am, you can't revoke your child's citizenship, only he or she can do that when they are 18.
Law says
To be eligible to renounce your Canadian citizenship, you must:
be a Canadian citizen
prove that you are or that you will become a citizen of a country other than Canada if your application to renounce is approved
not live in Canada
be at least 18 years oldnot be a threat to Canada's security or part of a pattern of criminal activity and
understand the significance of renouncing your Canadian citizenship.
http://www.cic.gc.ca/english/citizenship/renounce-eligibility.asp