@Ann10 Here's an example of a review that gets the important points across without falling afoul of the rules or appearing vindictive:
"____ left the house in clean condition. However, the stay did not go as smoothly as we hoped because, due to some difficulties in communication, resolving an issue with a misplaced key became more costly and labor-intensive than necessary."
I try to stop short of laying all the blame for poor communication on the other person, because it's a two-way street: if I'm not getting the answers I need, I have to acknowledge that I might not have asked all the right questions.
It's possible (though by no means certain) that you got an unfair retaliatory review from this guest. You will have an opportunity to post a graceful public response, and anyone who's worthy of staying in your lovely home can see that it's sour grapes - especially in light of your overwhelmingly positive 80+ reviews and your reciprocal review of this guest. This person doesn't seem clever enough to mask any bad intentions she might have.