Another link:
Discovery Health :: Pap Smear. This page notes that there are a lot of "false positives" associated with this test (which means that the test result says that there are abnormalities, but in fact there is no problem). The test is designed to be relatively easy to run and cheap to process; that way, testing lots of people doesn't run up big bucks. Then, if there's an indication of a problem, they perform a more rigorous test. There's a good chance that there is nothing wrong with your girlfriend, but it is important that she go back and get the follow up testing.
Thanks for helping your girlfriend out and trying to find out as much as you can; she will appreciate that. Help her figure out what questions she needs to ask on her return visit. I'm surprised that they didn't send her some pamphlets with the test result.