That's what I thought. A friends daughter has been left Uni for 6 years and still owes on her loan and is talking of going back, but I don't think she can if she hasn't paid off her first loan. We shall see!
Unless it's a particular degree (like nursing) your friend will have to finance her own degree. Regardless of whether she has had a loan before or not.
My husband did a degree in management which he'd paid for himself, and wanted to return about 4 years later to do an environmental health degree. He would have had to finance it himself as he had already been to university.