This is Anna's first real transformation. Anna travels with a caravan in my story, in that caravan is a girl named Moka who's something of a con artist. Noticing the new girl, Moka befriended the naive and trusting Anna only to drug Anna's food with her newest alchemic concoction a week later. It was not a fun experience for the poor girl as clothes tore off, feet and hands became hooves, and her voice turned into panicked brays.
Needless to say Anna no longer trusts two things: Food prepared by others and Moka; who of which seems to not understand nor indeed care that she did something rather cruel to the poor girl.