The reality is that sometimes, even if you win, you lose.

While I think she should pay 100%, there is some value in just putting this behind you. If you think the trouble you are going to need to go through to get full value back will be worth it, by all means go for it. Otherwise, chalk one up to bad luck.

It's more important to figure out what's best to do given your situation than it is to worry about who's right and who's wrong.