863211 and PJiang,help

my girlfriend is Canadian,08/17/09 she got the approval notice of H1B (I-797C) after Oct 1st 2009 , she is working as H1B status,but never been out of USA after 10/01/09, now she is planning to go to china for business travel, but she did not have I-94, is it a problem? if she need, where she can apply?which kind documents she need for come back into USA? should she need make a appoint with USA embassy in beijing to get H1B visa? thanks a lot