@Krystle5 - do as Airbnb suggests and if you are having any conversations with her off the platform, stop right now and only communicate with this person via the website or app. If you have the texts or emails, I'd copy them right into an Airbnb email and tell the guest that you would like to make sure you are only talking via the portal so all the conversations are in one place. This will also help if she's persistant at reaching out to you over and over. Since she is threatening you, "turning the neighbors against you" is essentially extortion, make sure you flag these communications for Airbnb to take note. https://www.airbnb.com/help/article/548/what-is-airbnb-s-extortion-policy
You've learned a very valuable lesson never to hold reservations for anyone. Additionally, if the guest who books is not staying at the property, that is a third-party booking and not allowed on Airbnb. https://www.airbnb.com/help/article/1311/who-can-book-trips-on-behalf-of-someone-else. Finally, your listing says very clearly no parties or events - right now there is a very good thread helping all of us remember to follow our own house rules and not break them in an effort to please our guests. https://community.withairbnb.com/t5/Hosting/Do-Not-Break-Your-Own-Rules/m-p/448901#M101617 . Finally, when someone doesn't have the money to book the property they want at the time they want it, this is a giant red flag that the guest is going to be difficult and a problem. http://globalhosting.freeforums.net/thread/455/red-flags-hosts
Good luck.