This is such a sad situation. It's awful that you have to suffer the loss of a cat that you became attached to and then have to endure the guilt of being blamed, not to mention the threat of a lawsuit for money. What a shame. I'm sorry for you that this has happened but there is no way I would give this woman any money at all! There is no court that could see any wrong doing on your part. Don't give in to this woman. If she had so much love for this cat she would have noticed that something was wrong with him before she brought him to you. Maybe she's feeling guilty and trying to lay the blame on you so she doesn't have to face the music herself.