[deacsoft]

The thing here may be that it's not $1,000 in the cops/courts eyes. You only have proof of $200 ($100 of which she payed back). So taking into consideration the veiw of the law, the real question is it it worth it for $100? I'd take a pass on that but that's up to you.
Secondly, the pay thing could come up but you're not the one on trial here. It could harm your credibility if you take it all the way to trial, but I'd think it wouldn't get that far. If it did it's remotely possible that the court could come after you for it but I find that very unlikely.
The best thing you can do, if your seriously entertaining the idea of going after her, is seek out a lawyer and a free consultation to see what your options are, your likelyhood of winning and what, and the possible consequences.