Which do you mean?
Children can sex humans from an early age, even their peers. Very occasionally they get it wrong and can get confused. If a child has made a mistake, that mistake should corrected. In that instance, it’s appropriate for a child to be “told” what sex someone is and what pronouns to use.
But you’re condoning the opposite: when a child is correct in identifying the sex of the human they’re describing, and using the correct sex pronouns, you’re saying children should be “told” that is wrong, and “told” not to do it. This is gaslighting children, abusive and a monumental safeguarding failure. Why do you support this?