We have a three-month guest (“tenant,” I suppose). We booked her directly and had her sign a three-month lease.
I’m posting this to say thanks to all here on the forum who provided me with info about direct booking and made me comfortable enough to try it.
We did this because our winters tend to be quiet, with far fewer Airbnb guests. One of our rooms is now filled until mid-March. The other room is still available on Airbnb.