Earlier quoted context omitted.
Then why on earth does Canada still put British monarchs on their money? Follow up question, why doesn't the US do it?
Canada doesn't. It puts Canadian monarchs on its coins. The fact that they are physically the same person as the British monarch is incidental.
So Elizabeth was a British monarch on Canadian money, and Canadian monarch on Canadian money, uniquely.
Of course she is no longer put on newly made money.