My only issue is that Rose's face looks scrunched and a little unnatural in this and the Doctor has a beak for a nose here. Rose's features need to be a little more rounded and not sharpened so much. If you gave her longer hair, I could confuse her for Jackie. And the Doctor just needs a smaller nose. Not by much, but by a bit.
Overall, I give 3.5/5 Very well done, but the facial features need to be right when designing art based on television characters/models/actors/actresses.