Q: Can I stay in USA while the papers are being processed? Im over 21 single, mom is citizen.

A: An adult child of a petitioning U.S. Citizen Parent is not considered an "immediate relative" as that term is defined in U.S. immigration law. As such, if the adult child has not maintained lawful status and is not in a lawful status at the time his/her spot in line in the family-based green card case becomes ready, then the adult child would not be eligible for adjustment of status. For example, if you are here currently in valid visitor status that has not yet expired, you should depart the United States on or before any authorized period of time granted to you OR try to change into some other type of valid nonimmigrant status that, perhaps, you can maintain all the way through the date that your spot in line in the green card case becomes ready (e.g., H-1B status). Of course, if you have already overstayed a particular status at the time of asking your question, you should also consult with an immigration attorney because there can be serious consequences that are triggered upon your departure from the U.S. (e.g., a 10-year bar to reentry if you had at the time of your departure more than 1 year of unlawful presence). You should consult with a competent immigration attorney who can ask many questions to flush out all possible issues, and then explain everything to you. Some attorneys, like my office, offer Skype and telephone consultations for those who are unable to attend an appointment in-person.