It's only for importing Outlook 2001 MACINTOSH version stuff.
But first, we have to definitely know what version of Outlook she's using on the PC. Often, people refer to Outlook Express when saying "Outlook", which is an entirely different beast from the application that comes with Office for Windows.
Either way, I think the most simple way is to install the free version of Eudora on both the PC and the Mac. On the PC, you import things from Outlook to Eudora, then export Eudora's settings to the Mac, there import it into Eudora and then let the final mail handler handle the import from Eudora.
Mac user since 1987. Running Mac OS X 10.9 "Mavericks" on a MacBook Pro Retina 13" & an iMac 27" and whatever's newest for my iPhone 5s, iPad Air and AppleTV 3.