"She wouldn't do that" is plenty helpful if you know the character.

Maybe you should start with a canon review of her reactions to being surprised and shown strange new things. It's most of what we see of her on screen during the credits, so it should be easy for you to find on youtube if you don't want to play through the ending again. Assuming you played it and didn't just watch a LP that might not have covered that. Take some notes on how she responds to the Kikwi and to being captured at Eldin Volcano.

Tone the stereotypical high-strung reactions down. You can still be comedic without being over the top.