@Tessy6
the guest obviously sent you an INQUIRY ( not REQUEST) . Anyone can send as many inquiries as he wants and then book or don't book.
You have set 1 day in the advance notice and I am not sure if she is able to book today, regardless of your pre-approval.
Anyway, you can also set "cutoff hours" to get a few hours for cleaning in case you make an exception and allow same day booking.
If you have instant booking enabled then you can also turn-off "Allow guests to send reservation requests without advance notice."
We usually clean the apartment as soon as our guests check-out but we leave the beds unmade until we get a booking and the exact number of guests.