We learned earlier this year that Samuel Anderson will be joing Jenna Coleman and Peter Capaldi in the TARDIS as Danny Pink who teaches with Clara at Coal Hill School. Now, it appears that the Doctor will be joined by a student of the school as well played by Ellis George.
While little is known about her character, with two teachers, a student and The Doctor in the TARDIS, the 12th Doctor is looking more and more like the First.