From what I am trying to understand, this guest has paid and booked your place?
If so, as @Marit-Anne0 mentioned do that.
I wouldn't worry too much if she has booked it, but if you fail to hear from her, just mentioned the pick up instructions any if she fails to do this, then that is her own responsibility to find out herself, but make sure that you were fully accessible should she needed your help. Her uncertainity is her own problem not yours.
If you do want to cancel, I AM ADVICING you to do it with great care. I once did when a guest booked and wanted to cancel immediately and with the lack of clear how to and a phone call to Airbnb I got penalised. My dates were blocked and I had a bad host remark. If a guest requests you to cancel NEVER NEVER accept it. This is where I got the penality from. They need to cancel through airbnb.
You can also argue you are uncomfortable with this guest who has not been communicative and very unreliable with their planning.
I actually said once to an Airbnb agent, I want to cancel because not only do they want to cancel but why would I would to have them stay at mine who doesn't want to stay there. I not allowing someone I don't feel good about staying there.
But I'm not too sure what you mean about taking risks and costs if they have already paid and booked ? or did they just enquire? I have never once held a booking, my place gets rented out all the time , so if they snooze they loose. I had one guest asking if the place was still available after 2 weeks asking.
My brain went silent with a cricket cricking when I read his message.
Like seriously. Get your act together, like most guests do. Like it booked it , with payment confirmed. BOOM, done.
Why does it have to be so hard?