"Called out your name?" she asked, frowning at him. Then she came to the obvious - and wrong - conclusion. After all, she had seen what regeneration looked like on someone else, she knew the theory behind it...

"Doctor? What have you done to yourself?" she considered, then grinned a bit. "Well, better than the bow-tie at least."

And thinking this was some other regeneration of the Doctor's she stepped forward to hug him.