Hi David, thanks for replying,
No problems running diagnostics on the iMac, she has all the discs. Not so for the TiBook (yeah, I know, I should've brought some), unfortunately, all I could do was fix permissions. That didn't work, same problem.
So, I'm stuck with making a disk image of her TiBook's drive on my portable FW drive, and now I'm going to have to move everything manually to the iMac (agony!).
Chas