Depends which country you decide to do,China is 2 years I think

I don't know about American.

For her green card,at first she might get an 2 year (we call white card)one first for couple years, if you divorce then she will lose it, you might need until she can get the Permanent one, that is safer. When they give you the interview for the permanet one they need you both there and show them evidence that you are still married.I am not a expert though.