I would like to express my regret that this is the way this guest experienced this situation. The sudden change of plans that were none of this guest's fault, also affected me very much. She was supposed to stay 6 nights, and sent a request to change her stay to 2 nights and explained that she wanted to go home earlier because of the circumstances with the train derailment. Although I am sorry for the things that happened, these were neither my fault.
As the guest's request to change the dates came on the same day as she would arrive, the chance of getting another booking for the remaining 4 nights were close to none and at first I denied the request, which is my right on airbnb. Then I felt bad for her and wrote her another message asking her to change the request to 4 nights in stead of 2, so that she would spend a bit less and I wouldn't loose as much.
On airbnb there is a policy for canceling, and this is there to keep both parties safe. I have a 5 day canceling policy because in my experience it's difficult to get new bookings if it's closer to the arrival date than 5 days, in case the guest should cancel. To adress the point that I wrote to her that I didn't find it fair to leave this up to my conscience, as she couldn't if she would have booked at a hotel, expecting that she could cancel because she made a choice to leave earlier, maybe this seemed cold to her and for this I apologize. It made me very uncomfortable as well, and in fact I did what I could, although it was not ideal for any of us. It was her own choice to pay money to change her plane ticket and go back to the US earlier, and I felt it wasn't fair that I should be put in a tricky situation for the monthly payments on my apartment because she made this choice.
In her review she writes that I mentioned that I don't do this for fun. This, I find, looks very harsh when it is taken out of context, as I also explained to her about the loan I have on my apartment that I pay every month and that I am financially dependent on the income from renting out this room. I enjoy very much being a host on airbnb and as 99% of my reviews reflect, my guests find me and my apartment welcoming. I have worked hard for this and will keep doing so in the future.