I see no one around whom you could possibly be disturbing. [Sebastian is the only other person within eyesight.
He takes another step towards her, stop short of coming too close. It's a disaster of a first impression she's giving, of course, but Sebastian doesn't necessarily judge her for it. He neither knows what caused this state nor what she is - he has no standard for reference. Besides, he's too busy wondering about these supernatural abilities to judge much. Gently:]
Please excuse me, but it would be wrong to simply leave without asking if you are sick or injured. [Which isn't to say he wouldn't.]