I am a US citizen can I sponsor a friend/business partner?

OK; a few problems here. You can't sponsor her in the way you would sponsor a relative (spouse/child/parent/sibling). You could only sponsor her for employment through the business - and then only if her background and the job qualify for some type of employment-based visa. They really should have spoken to a lawyer before leaving. If she had built up a year of "unlawful presence" - in most cases, a year since her visa expired before leaving - she is subject to a ten-year bar to coming back (three year bar if she overstayed 180 days before leaving) Had they stayed, there is no immediate way to legalize her status without leaving with a spouse who is a green card holder -BUT: if he would eventually have been able to naturalize as a citizen, he could then have filed for her and got her a green card here without her having to leave and become bar-subject. He can still try to natur4alize - perhaps - and apply for her, applying for a waiver of the bar, but it will be very difficult to win such a case, now. They should still speak with a lawyer here to see what might be done (and, maybe she falls under an exception where she isn't subject to a reentry bar). You may still be able to help with an affidavit, but probably not direct sponsorship.

More facts are needed to determine whether she will be inadmissible and for how long. Your business partner's green card will be lost if he left with the intention of abandoning his residence here. They should consult with an experienced and knowledgeable immigration attorney to determine their situation, identify relevant issues and available options, and propose reasonable shortterm and longterm strategies and solutions. Scott D. Pollock www.lawfirm1.com