Legal Question in Immigration Law in Washington

You need to file a petition (form I-130) and several related documents to sponsor her for legal permanent resident card. If at the time she entered the US, presumably with her parents, she went through a port of entry (in other words, she entered with inspection) then you can also file to adjust her status (form I-485 and related documents and forms) at the same time. 6-9 months later you will be scheduled for an interview at a USCIS office and after that, assuming there are no issues, she will get a legal permanent resident card (a/k/a/ a "green card").

If at the time her family brought her over, she did clear US customs and immigration, meaning she snuck in somehow, or if she no longer has evidence that she did enter after an immigration inspection, then at some point she will need to return to her home country for processing there. Depending on how long she has been in the US, she is subject to certain bars of inadmissibility for various lengths of time. It is possible to seek a waiver of those bars to admissibility and get her back here. If this is her situation, then I'd estimate 6-12 months that she will need to wait outside the US. Note, if she has to apply for a waiver to be admissible, there are no guarantees that it will be granted, which can result in a wait of several years before she would be allowed to return to the US.

To become a citizen, after she has had her green card for three years, she can become a US citizen. No matter what, I suggest you seek an immigration attorney to help you. I am happy to help, so feel free to contact me anytime at 206-223-9510.

Best of luck!