Internship is considered as employment regardless being paid or not.
-Then, let's use another name: Professional Skill Trainging Workshop, especially he paid the training fee and that is not employment at all. Do you see any employment you work for the employer and then, pay money to the employer? Anyway, H4 holder does not need to get the school International Office approved to get the training outside campus and also can get this kind of training even if he does not need to enroll in a shcool.
Overall, it is easy for the H4 holder to justify that this kind of training is legal. At least, it is gray area.
