Use any file manager. Open it and look at the drives and partitions
displayed in the tree structure on the left hand side. I use Dolphin, but
it should work just the same in any other - Nautilus, Thunar etc.

Unless you have an unusually large number of partitions/drives/Windows
installations it shouldn't be hard to find the right partition because it
will have a "Windows" folder in it. Open the "Documents and Settings"
folder in the same partition (not inside the Windows folder). The login
names of all users are found in the "Documents and Settings" folder and all
your wife's files should be in hers, unless she made a strenuous effort to
hide them elsewhere. In that case she will have to tell you where she hid
them! If you have more than one Windows installation you'll have to inspect
the files and see which one is the one you need to recover the documents
from.

Shouldn't be too difficult as Linux can see, read and copy any unencrypted
file Windows can create.