What problem does the woman have?

M: Hi, Mandy. How’s everything going?
W: Not too good, I suppose.
M: What happened?
W: Well, you know I moved out from Mrs. Henzer’s nine months ago. And all along I forgot to inform the registration office to get my address changed. Guess what? The library sent three reminder notices on the fines incurred on the overdue books and Mrs. Henzer kept the letters without returning them to the senders.
M: How did you find out?
W: Well, I went to the registration to get my transcript but they said there are some outstanding fines that I have to settle before they can release it.
M: Then just pay the fine and you can get your transcript. What’s the big problem?
W: Well... Yeah, that’s exactly what I thought but the fine came to $150 and that was a shock to me. I didn’t expect it to come to that much.
M: Ooh. That’s a bit of a bite! Did you keep the book for long? That’s the first time I’ve come across such a big fine on the library loan.
W: Guess what? I checked with the library and they told me three books are still outstanding. They’re from 8 months ago. I thought I’d returned them.
M: Are you sure you returned the books yourself or did you get someone to do it?
W: Well, hard to recall now since it was so long ago. At that time I was holding two jobs and had to juggle with school. I really thought I had returned them.
M: Tell you what. Why don’t you go back to Mrs. Henzer and see if the books are still there? Otherwise, you’ll have to pay for the lost books and I’m sure they will cost more than $150.
W: I guess that’s the only choice I’m left with right now.