Actually, that's less of a problem than you might think. There are lots of ways to fax documents without a landline -- or even a fax machine.

For starters, find out if faxes are even necessary. I'm guessing your sister's supervisor would be just as happy (if not happier) with PDFs delivered via e-mail.

If that's the case, many desktop programs (including Microsoft Office) can generate PDF versions of the documents you create. That's a pretty easy fix.

Another option: that supports faxing directly from Google Docs.

To send a fax, you simply open your Google Docs document, then click the "Fax This" bookmarklet (which you can add to any browser). Type or paste in the fax number and presto: the document gets delivered. In my tests, it took just a few minutes for outbound faxes to arrive.