Partially because it just creeps her out, but also partially because she doesn't like dead bodies. I think she'd have a lot of fears surrounding reanimated corpses based on killing the number of people she's killed -- and since taxidermy is the closest thing to a real reanimated corpse, it would creep her out and guilt her to no end.
Also. You've been doing a crapton of ref sheets lately and giving me a guilty conscience for not doing mine. I actually have a folder in my Ref Sheet folder that has all the sheets I need to redo in it, and lo and behold, I'm STILL NOT DOING THEM.