It's not about whether or not she'll end up being a good artist or how cute she is or isn't. If she continues doing this stuff, her life is going to revolve around being a celebrity. She's never going to have a proper childhood or know what it's like to be a real person. Her personality, ego, and worldview could become hugely distorted and she could end up becoming a terrible human being. Other little girls will see what she's doing and want to be like her, furthering the insane American cult of celebrity and the false belief that everyone is special and talented that's led to the hugely swollen egos and superficiality and shallowness that plagues this generation.
Her parents are sick for doing this to her and our society is sick for encouraging it.