Setting up an Apple ID

I just purchased a Nano for my wife and am trying to set it up. My computer is partitioned (her side my side) and I already have iTunes loaded on my side. I downloaded it to her side with no problem. When I went to set up an iTunes account for her and, in the process, establish an Apple ID, it stated her e-mail address already has an Apple ID and a password. She has never set up an Apple ID and my iTunes account does not include her e-mail address.

How do I correct this or find her password?

Many thanks in advance!

wm