Deeply frustrated with the airbnb service!
It sounds as if it would be easier if you just get guest to pay you directly?
The problem is you have been taking third party bookings, rather than asking the guest setting up an Aibnb business partner account, which meant you could have dealt with her in the event of damage by one of the employees.
As you have found accepting third party bookings against Airbnb's terms means you aren't guaranteed help when things go wrong.
Things are complicated:
Does "Caroline" own an Airbnb business account (obliged to book for employees), or is she making third party bookings with her personal account (which is against Airbnb terms) ?
So if no business account i can understand Airbnb wants to review her account. As @Helen3 allready mentioned: problems will arise with illegal third party reservations.