@Lydia-Jane0 There's nothing that you need to do from an Airbnb perspective - guests are generally responsible for managing their own health issues with respect to the local environment, and taking out the appropriate travel insurance policy for predictable emergencies. You have every right to uphold your cancellation policy, or you may offer a refund via Resolutions if you want to.
Business matters aside, I can only hope that the fact that your guest has busied herself with changing apartments, rather than seeking medical attention, means her present condition is not severe. If that's not the case, perhaps persuade her to get in an ambulance and deal with Airbnb later. They could take weeks to reply.
