Provinces aren’t states. The powers of the Canadian provincial governments are delegated to them from the Canadian federal government, not the other way around. Canada does not have a constitution that constrains federal power, since it was not formed by the uniting of states wary of federal power, but rather the uniting of colonies which all considered themselves to be under the aegis of a single sovereignty (Britain).
Fun fact: rather than each province having a plain-old governor, Canada (as any Commonwealth country) has one Governor General for the whole country; and then each province has a Lieutenant Governor, also appointed by the Queen, to serve under the Governor General.
Fun fact: rather than each province having a plain-old governor, Canada (as any Commonwealth country) has one Governor General for the whole country; and then each province has a Lieutenant Governor, also appointed by the Queen, to serve under the Governor General.