Rescind your offer of 400.00 and tell her you owe her nothing. Legally, you are only required to replace/repair the frig. It was her choice to eat out and she could have easy used a microwave, hotplate or bought non perishable items. I she deducts from the rent, then you know what kind of renter you have, and you know that you have to get rid of her. Hopefully, by legal methods.