Which character will become a teacher?

[Steve Vander Ark]

No: HPFGUIDX 24060

Okay, I'm stumped. I have listened to every NPR interview with JKR 
and have yet to find this quote. Can someone tell me exactly what she 
said? It doesn't seem logical that someone still in school will 
become a teacher, and it's pretty clear that she isn't telling us 
anything about what happens after year 7, so if this is true, it must 
be an older student who is coming back to Hogwarts to teach after 
leaving school. But I'd love to see the quote. Can anyone help me out 
here?

Steve Vander Ark
The Harry Potter Lexicon
http://www.i2k.com/~svderark/lexicon