I'm sure she wouldn't lie, but just advising that she should be very clear about her status.
From what has been said on GC in the past, it seems like AXiD, PhiSig and possibly DG accept grad students into their chapters. Out of those three, only DG is at your friend's school. I would advise her to do some research about the policies of the sororities at her school. And also, she should check with the school's greek life office, perhaps they may have a rule at the university that only undergrads/first BA/BS candidates may join.
Here are some other threads that may be helpful:
http://www.greekchat.com/gcforums/sh...ht=bachelor%2A
http://www.greekchat.com/gcforums/sh...ht=bachelor%2A