Reminder that, Sanae, as a priestess of the Suwa Taisha, most likely knows how to kill, butcher, disembowel and skin a deer and has done it countless times before. They have (or well, had) a whole festival about this where at the end they offer deer heads to the kami.
Suwa Taisha is unique in allowing people to hunt deer, even though hunting is usually frowned upon.
See? She can be cool! And a little morbid. She's not all cute.