If the last fingerprints (biometrics) were done over a year ago, then USCIS will ask for an updated set of fingerprints. Does asking for a second set of fingerprints means she will have an answer soon? No. Will she have another interview? It depends on whether or not she has any issues that would impede her ability to naturalize. Why did it take so long for her to get her interview in the first place? Is there someone in her family who is being investigated for immigration fraud? Was your friend ever arrested? Did she ever register to vote? Was there a problem with her original application (for example, did she have a "bad I-9" where she claimed to be a U.S. Citizen in order to be able to work?). If she doesn't hear back for a while, she can ask what the status of her application is at the USCIS office. If they say "background checks" then it is likely some kind of investigation. Try to find out if ICE has her file or if USCIS still has it. If ICE has the file, she is being investigated and she needs to get a good lawyer asap. Naturalization cases can be subject to "background checks" for years and years. If hers goes on this long, her lawyer can file a Mandamus action to force the government to make a decision but that decision could be a denial (and deportation if there is something in her past that would render her deportable).