BUT she's depicting herself as a schoolgirl, i.e. below the legal age, which according to the law you quoted is illegal. Then of course you do get adult women who have bodies that look underaged, but they are over 18. According to the law they aren't allowed to work in the porn industry. That is how I'm interpretting that, and it's kinda silly.
You are confusing real, identifiable women released on film and photos who can be traced in government databases via their birth certificate and social security number, and have agreed to written contracts to sign over the rights to release their private media to legitimate studios in the porn industry, with drawings or computer-generated images of child-like non-real persons.
Watching Tori Black in a Catholic schoolgirl outfit and pigtails do the deed is not equatable to an IMVU model meshed to look like an underaged schoolgirl simulate sex positions--but you have to take my word for it, she just turned 18.