Call it what it is. It’s sexual exploitation of child.
Aren’t there laws that are designed to protect minors from this kind of exploitation?
Yes, yes there are
18 U.S.C. § 2251 - U.S. Code - Unannotated Title 18. Crimes and Criminal Procedure § 2251. Sexual exploitation of children
http://codes.findlaw.com/us/title-18-crimes-and-criminal-procedure/18-usc-sect-2251.html
Also there are child labor laws that should prohibit this kind of exploitation.
The main federal law is Fair Labor Standards Act (FLSA). Child labor provisions under FLSA are designed to protect the educational opportunities of youth and prohibit their employment in jobs that are detrimental to their health and safety. FLSA restricts the hours that youth under 16 years of age can work and lists hazardous occupations too dangerous for young workers to perform.
https://en.m.wikipedia.org/wiki/Child_labor_laws_in_the_United_States
And, it’s possible her parents could be charged criminally for sexual exploitation of their own child.