The cancellation policy states that should a customer cancel they should pay the carer the required notice period, being 2 weeks for established relationships.
The Carer will not have any ongoing work and will find it difficult to find alternatives given the current circumstances and this notice is their lifeline. If the customer is being cautious it is correct and their prerogative to do so, however the carer has committed to take their booking and is available and able to work and so should be paid.
If the pause in schedule is due to the customer displaying symptoms, it may be sensible for the customer and carer to agree a compromise for the period of quarantine. This will enable the carer to return to work once it is safe to do so.