Welcome to the Forum and sorry to hear you had such a shit punt. She came up on my search results just recently but I rejected her immediately at £100 for half an hour. Negative feedback on here in arguably more useful than on AW but, if you want to leave something on AW, this is how to do it. Make a dummy booking for, say, either the middle of the night or at very short notice (this is to avoid her reading it, being able to accept it and then being able to leave you a negative) then write your feedback immediately after the time of the end of the booking. It will not show in her stats but as "Feedback only" in AW, which to me is equally valid. She can then choose to hide her feedback if she wants but that sends a very clear message.
Thanks for the useful review anyway and better luck elsewhere.