Hello @Retha1,
There's nothing you can do yourself to clear the calendar.
Since the guest has not responded you could contact Airbnb support to ask them to contact the guest.
Make sure to emphasise that you're still willing to host the guest for those dates, that it's she who has emailed saying that she wishes to cancel.
If you receive a notification or email saying that the guest wishes to cancel decline it. If you accept or ignore it you'll be penalised as you'll be deemed to have made the cancellation.
Steve.