You can go to prison for that. Major league fraud against the U.S. government and INS. Both she and the Ethiopian guy should go to jail.
I used to work with Japanese ladies who were married to Americans. Immigration officers went to their homes and interviewed the ladies and husbands separately. They were asked questions like “What side of the bed to you sleep on?” “What kind of underwear does your husband wear?” The immigration officers want to make sure that the Japanese ladies are not in a sham marriage. Apparently U.S. immigration authorities do not care about sham marriages involving people from Africa or from Muslim countries. What kind of problems do we have with Japanese immigrants??