"I know she doesn't like you very much, Doctor. She doesn't understand why I do and that makes me a bit nervous. I'll feel more comfortable knowing you're alright," Rose answers honestly. She doesn't honestly think that Morgana would physically hurt the Doctor but she does think Morgana would carelessly toss verbal barbs that would hurt worse than anything physical. Her Doctor is far too broken for Rose to tolerate anymore breaking if it can be avoided at all.