WS- what do you mean, allowed? You don't allow anyone to make anything. What would matter would be any action they commit which could be considered child molestation, unless you refer to the creation of child pornography, which is a very different matter. Both are illegal. The creation of art of unspecified content is not. Otherwise, we would have to arrest anyone who makes hentai. You cannot prevent any sort of crime by forbidding people any means of expression which presents their interpretation of the crime or its rammifications, if that be lterature or art.