I have been silently following this thread, because as I don't sell cookies, it is only theory I can offer. BUT, international trade is my business, I at least know a bit about the generals.
So, let me summarize: You sold cookies to some lady from overseas who actually talked you into this, as you normally only ship locally. You mention in your terms that you don't take responsibility for breakage during transport. And still you feel the need to replace her broken cookies free of charge so she won't give you a bad review on etsy???
If she had contacted me nicely I would have offered her replacement cookies foc, if she paid for the freight. If she was rude, not even this. Cause honestly, that was a clear case.
Maybe I am strange, but I have been working with customers for more than 20 years now. There are just some who rip off your whole arm when you offer your little finger. Sometimes it is better to risk a bad review (and add a statement below it to clarify the facts), than to let yourself get fooled 