Rumors about new Doctor's companion

If you watched seasons one or two of Skins you will know Cassie, a.k.a Hannah Murray. There is rumor that she will be the new Companion for the upcoming full season of Doctor Who.

I only known her from Skins so of course I see her as her character, a spaced out, drugged out, suicidal teen so I'm not sure I can see her working for a season long companion to the Doctor.

With the new Doctor being so young I know a lot of people are worried, and I haven't been yet...but this addition would make me worry that they are turning it into a teen based show. God knows I love those kinds of shows too but, it is different somehow.

Anyway, I'll keep my mind open and fingers crossed. Also, it is total rumor at this point so this could be totally garbage.