A guest has cancelled, which is fine. my cancellation policy says that she will receive 50% back, but she has not received anything. She has asked me to see if I can sort it, what can I do to help her?
If you look at the Airbnb Help Centre it will outline how cancellations work on Airbnb.
In summary once the guest cancels Airbnb will process the cancellation in line with your policy. If your guest wants to chase up on her refund she needs to contact them directly.
Your cancellation policy is strict. When a guest cancels at least 7 days before before check-in, the guest receives a 50% refund (excluding Airbnb service fees). This should also be mentioned in the information recieved when cancelling. If something does not meet expectations, guest can contact Airbnb: