As I said over on Fauna, this act of dishonesty is completely disgusting and her response utterly immature. You very clearly have proof of her misconduct, and others have even stepped forward to corroborate your story. I'm sorry to hear about this. It is always sad to learn that one who was thought of fondly in the community is actually a despicable, dishonest thief.

I hope that somehow you manage to get your mouse back, and that when/if you do, she is still as healthy as the day she arrived.