Probably shouldn't tell border patrol you're doing unpaid labor in a country you're visiting. When speaking to authorities it's best to say the absolute minimum required for the encounter.
She was on a tourist visa. She should have gotten a J-1 visa who can do 20 hours/week part time work with some constraints. Some details about this visa: https://yfuusa.org/2024/05/16/j1-student-visa/