If a person on b-2 tourist visit marry's a man she knows is legally separated but is not divorced what happens?
If he was not divorced, then he is a bigamist and can end up in jail. The marriage would be annulled and declared void.
If a person on b-2 tourist visit marry's a man she knows he legal separated but is not divorced what happens to her visa?
If a person on b-2 tourist visit marry's a man she knows he legal separated but is not divorced has she broken any laws?
How can someone who is in the USA as a tourist from Mexico get divorced from his wife who lives in Mexico?
Legally speaking you can't. That is the whole point. If you are in the US illegally, you can't legally work there. Even if you are in the US legally, you can't necessarily work there, for example, if you are on a tourist visa, or some student visas. Practically speaking, I suppose you need an employer willing to ignore the law.
In general, marriages which are legally performed and valid abroad are also legally valid in the United States. The embassy or tourist information bureau of the country in which the marriage will happen is the best source of information about marriage in that country. That being said, you still need to get a U.S. marriage license