Why does the woman want to start working at the art museum before the current semester ends?

Listen to a conversation between a student (S) and an employee (E) at the university art museum.
S: Hello, excuse me. Is Nathan here today?
E: No sorry, he’s gone for the day. Can I help you with something?
S: Well, i hope so. See, I’m supposed to start volunteering as a tour guide on Monday. I’m scheduled to give a tour at 10.I did my first volunteer training session with Nathan the other day and I was supposed to have the second sess’on tomorrow afternoon, which I understand is the last session that will be offered this week, right?
E: Yes, it is. In fact, it’s the last one we have scheduled for this semester.
S: Yeah, that’s what I was afraid of. So, I’m not sure what can be done because I’m scheduled to give that tour on Monday and it turns out I have to make up a test tomorrow afternoon.
E: Hmm... well, yes that is a problem I’m afraid, because we do require two training sessions before you’re allowed to start giving tours.
S: I know. I was hoping maybe I could work something out with Nathan. He gave us his home number at the original training session, but I’m not sure where I put it. Could you possibly give it to me again?
E: Well, no. I’m not allowed to give out employee’s phone numbers. It wouldn’t do you any good anyway. Nathan can’t waive that training requirement anymore than I can, but I can sign you up for the first session next semester and you could start giving tours then.
S: Thanks, but that might still be too late. It’s not that I wouldn’t want to do tours next semester. I would like to keep doing it. It’s just that... see, I really need to start this semester. You see my art history professor gave me a chance to improve my grade. He said I could get extra credit if I wrote a paper for him and volunteered here at the art museum.
E: Is this Professor Tyler’s class?
S: Yes, that is correct.
E: OK, I thought so. You’re not the first student he has referred to us. Look, did he specify that it had to be as a tour guide?
S: Well, not exactly. I just thought...
E: Because believe me, we could use you in other capacities.
S: Really? Like...
E: Well, it’s not as glamorous as being a tour guide, but we always need people to work in the museum gift shop or in our administrative offices. How are you at data entry, data analysis, stuff like that?
S: Pretty good actually.
E: Because we desperately need someone right away to help us keep our membership lists up-to-date, work on our monthly newsletter, things like that. I know it’s kind of boring, but once you get the hang of it, it is pretty rewarding. lt could even lead to a paid position.
S: Well, that’d certainly be a plus. Tell you what, let me just check with Professor Tyler, make sure it’s alright with him, and I’ll get back to you tomorrow. Would that be ok?
E: Ok! Great!