[x] Shove the old ghoul aside without alarming violence (he's no threat to you physically, and you don't want to spook Amelia), place a warm and fatherly hand on the girl's head, and talk her spirits up.
"Don't listen to him, lass. Don't stop fighting now. All of life is a fight. Have hope! I bring good news and glad tidings for all of the lost and the sick and the weary. Hang on just a little longer, and I'll tell you all about a wonderful God and a wonderful man named Jesus, who promises to take on all of your ailments and burdens. To make you a new person, whole and healthy and beautiful."
And if that falls through:
[X] Put a ward around Amelia, so even if she does turn into some monster she won't go around killing these apparently-innocent people still around.
-[X] You don't give a fuck if she kills the evil ones, though.