What is the woman’s main purpose in this conversation?

W: Dr. Newbury, could I speak with you?
M: Sure. Come in.
W: I need to ask you to let me take the final early.
M: May I ask why?
W: Yes. It’s because I bought a ticket to go home for Christmas, and my flight leaves on Tuesday. That’s the day before the exam.
M: Yes, well, Penny, the exam schedule is printed in the registration mate rials. You had to know the dates. Why didn’t you buy your ticket for the
day after the exam?
W: Truthfully, I just made a mistake. And now, I’ve got a real problem be cause the ticket is nonrefundable, and I can’t afford to buy another one.
M: Hmmn.
W: Dr.  Newbury, I live too far away to get home for Thanksgiving and Spring Break like the other students do. This is my only chance to see my family during the school year.  I’m sorry that it happened, but couldn’t you make an exception this time? Or could you give me an in complete and let me make it up next semester?
M: Okay. Anyone can make a mistake. You can take the exam on Monday.
W: Thank you. I really appreciate this.