The timing between the divorce and the new marriage will raise an issue. But if you put together a good package of bona fide evidence and testify well at your interview, then it should go well. Hire an attorney to represent you both throughout the process.
You do not state what your status is. Assuming you are a USC then you can sponsor your wife aas soon as you are divorced from your current wife. However, if you sponsored your current wife there are some limitations. To sponsor one wife while living with and having a baby with another woman may raise some red flags. You need to consult with an experienced family immigration attorney before you file.
GENERALLY, one may adjust status after marriage to a U.S. Citizen following a legal entry into the U.S. Your case will depend on the circumstances of her obtaining the visa (dual intent), whether there is sufficient income in your household to sponsor her, as well as her criminal history/past immigration history etc... I suggest that you visit a good immigration attorney to be sure.
Congratulations on your baby.
First, if your girlfriend last entered the U.S. with inspection but is an overstay, the good news is that she may still be able to file for and obtain her green card from within the U.S. based on marriage to a U.S. citizen. It is true that while most individuals who are here as overstays and/or have worked without permission are ineligible to obtain permanent resident status from within the U.S., this is not the case if you are applying for permanent resident status based on marriage to a U.S. citizen.
One big issue in her case is proving her last lawful entry. If she had a passport stamped or she was documented in anyway (I-94), that makes the process much easier.
Addressing the last lawful entry issue, she may still be able to pursue permanent resident status from within the U.S. based on marriage to a U.S. citizen. This is generally known as the adjustment of status process and requires filing the I-130, I-485, I-765 (work permission), I-131, I-864 affidavit of support, I-693 medical etc.
You can find info on the green card process based on marriage to a U.S, citizen at:
Another issue is whether CIS will determine that she had the intent to stay permanently when she last entered as a visitor. Her intent at that entry may be questioned at the adjustment interview.
Another issue is that you cannot marry until your divorce is finalized. Of course until that time she is here w/o status as an overstay, and that is never a good situation.
Another issue to understand is unlawful presence. Depending on the length of her overstay, she may have accrued unlawful presence so that if she were to depart the U.S. she could trigger a 3 or 10 year bar to returning.
Lastly, if you sponsored your soon to be ex-wife's green card, a subsequent marriage may be scrutinized more heavily and overall you may be questioned about the legitimacy of each relationship. Also, you may continue to have an affidavit of support issue for your ex-wife while taking on a new affidavit of support requirement for your new wife.
Overall, given the number of issues in your case, you should consider consulting with an experienced immigration attorney.
Andrew M. Wilson, Esq.
Serotte Reich Wilson, LLP
It sounds to me like you will need experienced immigration counsel to handle this matter. I am assuming that yours and your ex wife's marriage was a bona fide one and therefore it should have no impact on this new case for your girlfriend. The question may be raised at the interview by the examiner but should be satisfactorily answered if, again, your previous marriage was bona fide.
If your girlfriend legally entered the country and she is unlikely to become a public charge (which you will establish through financial documentation of the I-864 affidavit of support), you can petition for her as her husband. Again, I would seek legal counsel.