I am a permanent resident here (have been here for 6 years); I am graduating from law school next month. My mom is in Russia; she is 58, a widow, but gainfully employed, has two apartments, good income, and my brother with his family. She has already been denied a visa once (4 years ago). What are her chances of getting a visa to come to my graduation, and what can I do to help the process?

I would really appreciate your advice!