Can an alter ego be good?

I'm working on an english project that includes finding the alter ego in the characters of a book I'm reading (The Fringe and the Fury). Kellan, a strong-minded female character who supports the government's idea of "only the strong survive", changes her ways once seeing the wrong in the cities. Would this be considered an alter ego--being originally arrogant and self-centered but then suddenly becoming kind and caring? Or would this go the other way (she has always been kind and caring, but has been showing her alter ego the entire time she was in the cities)?