I don't see where you have gone into the router interface to see how it is currently setup.
has been given a linksys wrk54g ethernet wireless router
By whom? From where? Has it had a different user/password for connection saved in it? Has it had a static IP configured? Have you gone to the router status page to see if it even HAS an external IP address?
If you don't have the manual for this router, go
here to get it. Access the router interface via the browser on the computer the routers connected to. The manual will tell you how.
As you have no history on how the router was setup, i'd strongly suggest holding the reset button for 5-10 seconds to set the router back to the default settings before doing anything else.
Also:
i plugged in her work laptop via the ethernet cable directly to the cablemodem and still no browsing
. You have checked the browsers proxy settings to make sure that its not set to go through a company proxy, right?
Get an ipconfig /all from the laptop connected to the modem, the laptop connected to the router, and a screenshot of the router status page, then get back to us.