Unfortunately, as a 21 years old, you no longer meet the definition of "child" under the immigration laws. Your mother can sponsor you after she becomes permanent resident. There is a backlog, however, for adult children of residents and, depending on your country of birth, the wait could be 8 years up to 19 years. I should also caution you that there is no category for married children of permanent residents, so your mother could not sponsor you if you get married. If your mother naturalizes, then she could sponsor you regardless of your marital status. I hope this information is helpful to you.
Mark J. Curley
www.curleylawoffice.com
Answered on Sep 09th, 2011 at 1:35 PM