Your mother has the burden to prove she was inspected and admitted. An I-94 is proof of admission. If she has a legible entry stamp in her passport this will likely be sufficient. If the entry stamp is not legible, you should consider filing the Form I-102. You can read more about family-based immigration at http://myattorneyusa.com/family-immigration.
Answered on Feb 17th, 2016 at 5:11 AM