She’s from the same hospital that Duncan went to. It’s logical to assume she was exposed to him in some way.
The question is how many people has she exposed. When did her symptoms start? And more importantly when did she become contagious?
More than a few I would suspect. I don't believe a single solitary word that comes out of the mouths of the CDC. They are all a bunch of professional liars. I'm sure they had to have known there was a very good chance that others would be infected by this African guy, yet it seems they did everything they could to minimize the danger. What A holes they are.