What happens to me if I marry someone who is living illegally in the United States?

No. If she entered the U.S. unlawfully, even if you marry her, she is not eligible to legalize her status within the U.S. under the current immigration laws. There is no automatic anything for her. The child will have U.S. citizenship if born in the U.S. but unless the mother entered the U.S. lawfully, she is not eligible for any immigration benefits even if she marries you.

You would need to show the good faith nature of the marriage, which a child together will clearly assist with. I am not clear if the two of you are living together or not however. It is not automatic, and an application for an immigrant visa will need to be filed. She will also need to qualify for adjustment of status. It may be best for the two of you to have a consultation with an immigration attorney together to fully discuss what the options are.

She will not become a citizen, automatically or otherwise. She must first become a permanent resident, and she can do that only if 1) she marries a U.S. citizen or permanent resident; 2) her husband files an immigrant petition for her; and 3) the Immigration Service approves the petition - which is not going to happen if the mother of your child came to the U.S. without a visa. If the woman you think of marrying came to the U.S. illegally, the procedure becomes much more complicated, and you should talk to an immigration attorney and see what are the chances of success in this particular case.

There would not be any impact to you. Once you are married you May petition for her to become a legal permanent resident. There are various ways to go about her actually receiving the benefit. If she came to the United States legally but is simply out of status she may request to adjust status in the United States, for example if she came in with a tourist visa. If she came in illegally she will need a waiver and I would strongly suggest you consult with an attorney. She will not receive any benefit as far as immigration us concerned just by marrying a United States citizen.

From an immigration point of view, nothing will happen to you if you marry someone who is in the US illegally. However, just because you marry that person, it does not mean that they will automatically become legal. Depending on how they came in, when they came in, etc. they may or may not be able to become permanent residents of the US. You should consult an attorney about her specific set of facts to find out if you can actually help her by marrying her.

No. She does not become a US citizen automatically. How long it takes will depend on the particular facts of her case. At a minimum, however, you have to submit a relative petition on her behalf and she has to apply for adjustment of status or for an immigrant visa. If she entered the country legally, she can apply for adjustment of status on form I-485 with USCIS. If she entered the country illegally, she must apply for an immigrant visa at the US consulate in her home country unless she qualifies for an exemption, such as 245(i). Your relative petition on her behalf is submitted on form I-130.

No, she will not become a citizen or a legal resident automatically. You have to file for her, but first, you need to determine whether she can adjust her status here in the US or whether she must leave the country and consular process back into the US. This depends on whether she originally came to the US legally, with a visa, and overstayed, or whether she just illegally crossed the border. If she crossed the border illegally, she would have to return to her home country ultimately before she can legally return. But she would need to obtain an unlawful presence waiver first. The process could be complex. The point is, if you marry her, there is nothing "automatic" about her status and nothing is just a given.