My guest wants to stay another night so I have sent a request to her to change the dates - meanwhile that date is still showing as available on my calendar. Can someone book that date while the request is pending? Or should I block it out?
If it is possible, i think, it is as normal reservation that you need to tell your guest, to send you a booking request and you can approve it or your guest could prolong the same reservation.
She seemed worried that if she changed her reservation she would lose the whole time. I have taken off instant booking temporarily (till tomorrow) until she responds to the request.
Remind the guest that they have to confirm the request in order to get the extra night. You could block it off, but then if they choose not to book the extra night you loose your ability for a different guest to book.