The first thing you should do is ensure that she never becomes an illegal immigrant.
If the two of you are ready to marry, she should come to the US legally, with a passport and visa, and marry you here, or you should travel to Mexico legally, with a passport and visa, and marry her there.
Either will technically work, but if you are planning to live in the US after you are married, then it would be best and easiest in the long term for the marriage to have taken place legally in the United States.
In that case, you should seek a 'Nonimmigrant Visa for a Fiancee' for her (see link below) and then follow the proper procedures to have her become a citizen (see second link below).
They should have checked it properly. It is still illegal.
In 2011 Mexico decriminalized illegal immigration, thus becoming an administrative infraction punishable with a fine that stays around US$500. Mexico also recognizes dual citizenship, so all you have to do is to define your status, pay the corresponding fine and begin the process to acquire legal residence through the FM2 (immigrant) process. You should however, consult a legal advisor.
You are in a messy situation. You should talk to a lawyer.
Yes
Yes, a will is a will regardless of wether the person was a legal or illegal immigrant. As long as it was executed according the the laws of the state it is being probated in and the will is allowed by the court, their immigrant status should not matter.
If the immigrant married a US citizen, then that's a done deal and she is no longer illegal. It sounds like you need to take care of your own affairs, starting with divorce proceedings.
the US citizen shouldn't
No, although I am all for people who enter legally and gain citisinship, I don't want illegal immigrants in the US. I don't know why people think it should be ignored, why would we call it illegal immigration if it was allowed?
absolutely not.. i know it's tempting .. but don't contribute to the problem... be part of the solution.. you knew the answer you'd get..
No, You cannot. You should have known better that Latinas don't take fools seriously!
The illegal immigrant should go back to his or her home country and complete the divorce with his or her spouse. Then you should either get married in that country and apply for a spouse visa, or go visit that country and upon returning apply for a fiance visa and get married in the US after the fiance visa is granted.
NO, it is unlawful for the illegal alien to be present in the country. It is unlwaful for any employer to knowingly hire an illegal alien. The illegal alien should immediately leave the country if he/she wants to comply with the law.