Who is the visitor?

W: Can I see Mr, Johnson, please? I’ve an appointment at 10:30.
M: What’s your name, please?
W: McDonald, Jane McDonald.
M: Ah, yes. Mr. Johnson’s expecting you.

M: Hello, Jane, I’m wondering if you’d like to join us for disco this evening.
W: Oh, I wish I could, but I still have a paper to discuss with Profess Smith this evening.
M: Oh, it’s a pity! Then what about tomorrow’s party?
W: I’m free tomorrow.