To borrow your own style of argument -- distinctions without differences -- the child does not consent to be a celebrity, and is therefore protected in the same way as the unfortunate Austrian children mentioned by another poster.
One consents to engage in sexual relations.
One consents to enter into binding legal contracts.
One consents to a variety of things, but in all things requiring the notion of consent, there is at root a choice. One can refuse to engage in sexual activity. One can refuse to sign a contract.
Celebrity, however one may wish the term be used, is not something one takes unto oneself by voluntary action, nor can one refuse its loving embrace. Celebrity is bestowed.
Fickle though it is, arbitrary as the public's taste appears to be, celebrity is bestowed on hero and villain alike, on rich and poor, with good consequences and bad.
One thinks of politicians and movie stars who seek the limelight and revel in celebrity - but many are those who seek such acclaim in vain.
One also thinks of the Richard Jewels of the world, celebrities against their will, while the world reviles them for crimes they did not commit and ignores them by revoking that same celebrity when it is found they were entirely innocent - and in fact, heroes.
From Joey Buttafuco to the late Teflon Don, from the late Richard Nixon to the late DC Madam - celebrity targets whom it targets. One does not choose to engage celebrity, and consent is not required.