Lack of communication

[Tommaso10]

Hi all,
Tomorrow I should welcome a guest, however I have tried to get in touch with her by email and by telephone during the last week to arrange the chek in with no luck.
Last time I have received a message from her was almost one month ago when she booked my place.
Knowing that I have a flexible cancellation policy what would happen if tomorrow in the evening I cancel her reservation?
Did any one has already had a similar situation?
Thank you a lot in advance for your help and kind regards,
Tommy