Ok so this might be a bit of a yappage but
The character isn't necessarily a representation of the creator. For example, the characters in Quentin Tarantino's Resevoir Dogs are racist and say the hard r n-word over and over again, but does that make Tarantino a racist? No, it makes the characters a racist. So I believe that creating a character with unacceptable beliefs such as racism (or pedophilia in this case) is fine, as long as the creator doesn't support or associate themselves with said belief.
(Just to note, I don't know shit about Vivziepop, her OCs, or her lore. She might support Mirage's pedophilia, or be a pedo herself, who knows)