I tried searching their boards and there are a lot of people talking about having too many names, which is apparently something they were asked to fix in the last course revision... and someone else said they didn't think the right choice was "getting rid of all of them", so maybe that's what happened? And of course it could be that you have to get further in the course before they introduce more characters, but three or four still seems awfully parsimonious...

But maybe the other woman was Siobhan, because somebody mentioned how awesome she was on the basis of hobbies and being a lesbian?