Ds1 isn't interested in cutting/killing things but he is absolutely fascinated atm by what the body looks like inside. His favourite book is one that has lots of simple drawings and explanations of what the body looks like and what each part does. His special interest is the intestines and bowels.
It sounds as though your dd is thinking in a similar way but, unlike my ds1, she has made the connection that you can cut things open to see what they look like inside.
You can buy regurgitated owl pellets that have undigested animal bones inside from The Great Little Trading Company. Would that help her to understand what's inside? My dd asks about blood and bleeding and if she did x y z would her blood come out. She 5 yo in October so it's just a curiosity thing I think