Have them get a consultation with an immigration attorney to see if they might qualify. Here's some info I will paste here:
Under U.S. immigration laws, there are potentially three methods to qualify for a model's visa: the H-1B WORK VISA, the O-1 ALIEN VISA and the P-3 CULTURAL EVENT VISA:
The H-1B work visa allows you to do modeling work in the U.S. for a designated employer for three years. This visa requires that you present: 1) qualifications as a distinguished fashion model in the industry, including titles in widely-regarded contests of first rank; and 2) a written job offer from a U.S. employer which has offered you the "prevailing wage" and filed a Labor Department "attestation".
The O-1 alien visa allows foreigners of extra-ordinary skills and talents to visit the U.S. for twelve months. This visa requires that you show: 1) A major international award or prize, or 2) Other significant awards or prizes, or contributions to the field, or well-paid employment, and 3) a consultation report from a peer group, labor union or management organization verifying the alien's credentials and the benefits of the visit. See Matter of Ford Models, EAC 92-171-50777 (AAU Oct. 16, 1992) which allowed the O-1 model's visa.
The P-3 cultural event visa is available to "artists and entertainers" who come to the U.S. to participate in a "culturally unique" event or program which furthers the art form. This requires that you show: 1) skills and talents which are authentic and supported by recognized credentials such as prizes or awards, published articles about your accomplishments, and letters from leaders explaining your performance, 2) your performance is "culturally unique" based on newspaper or other written review, and 3) a consultation report from a peer group, labor union or management organization verifying the alien's credentials and how the event is "culturally unique".
An example of a "culturally unique" event might be a model's trade show sponsored by an American company in the United States to showcase the beauty and modeling skills of the ladies of Medellin or Cali, Colombia (respectively, "Paisas" or "CaleÃ±as") widely-regarded, according to Fodor's travel literature, as "among the most exquisitely beautiful in all of Latin America".
I'm not an attorney - just work in the immigration industry. Hope this was useful and best of luck.