The LPR/LPD solution should work, as long as there is "IP connectivty"
between the two computers.
For example, the Win2K laptop is probably configured to use DHCP for IP
settings. If your home network does not have a DHCP server (e.g. an XP
computer with ICS installed, a router), you may not have any network
connectivity between the two computers at all. Can you "ping" between the
computers successfully?
You should be able to get normal Windows file and print sharing to work in
your situation, as long as there is connectivity as explained above.
Add a local user account on your home XP computer that has the same username
and password as your wife uses to logon to the work domain. Then, your XP
computer will "know" about your wife's user account and you should be able
to file and print sharing working.