I can understand why you would be anxious to have your thoughts straight on the matter, before being confronted with who knows what expectations on the part of the buyer. But I found those quotes from your contracts very straightforward: there's no doubt in my mind that the contract she signed puts the ball squarely in your court, i.e you are not obliged to refund her a penny. Now, if the circumstances are such that you are interested in some brownie points, you might consider what portion of her payment you might be willing to return -- but only as a PR gesture, not because of any real or perceived entitlement. She is not entitled. And she strikes me as a poor candidate for pet ownership. There's my two cents. Good luck.