My interview involved a group interview up first. My advice here is to research the company, where they fly to, aircraft etc. Also just general questions on customer service etc.
Then we broke and were told to wait for a phone call, if you recieved a call within the next hour you would need to come back at an appointed time in the afternoon for a one on one interview.
One on one interview was more questions on customer service and a few "how would you handle this?" questions.
Great company, very down to earth and friendly. Biggest tip....do some research, it will pay off.
Good luck to her, hope she is very successful.