@Ramsey14 It's unclear from your post if you have talked to Airbnb customer service about this, or only with the host. There were clear policies about full refunds for COVID for bookings made before March 14, for stays before April 14th. Then they kept extending the cancellation dates as it was clear that the pandemic was still raging.
When was the booking check-in date? Have you only been communicating with the host? If so, you may as well stop that, because she's obviously not going to relent. It's Airbnb you should be dealing with at this point, and if they are refusing to refund you in full, I really don't know what to suggest except persistence.