Welcome to A2K - and yes... it is a tricky situation!
Mmmm.... this is difficult to answer. You haven’t said if your daughter has been in trouble before or has a history of taking anything. Quite understandable not to say that " but it’s difficult to give an opinion believing you are going to make a decision based on these replies, to the information you have given us here.
If your daughter hasn’t been in any trouble before and struggles with anxiety (you mentioned suicidal " that’s a big statement which I wouldn’t imagine someone says without having cause, which says to me there is something far more deep rooted going on) " well, I would not take the risk of an 18 yr old who has had a “clean sheet” possibly ending up with a criminal record, if that’s what could happen. (I wouldn't know that)
Kids do a lot of things " and yes, should be held accountable for their actions. This is a year down the line and I think, from what you have said, even your discovery of the item may cause her a serious issue. This needs to be addressed.
I’m not sure really what would be the right thing to do " yes, I think kids ought to be accountable " but then again, kids do make mistakes. If your daughter had stolen something that was not valuable from someone else, or say, for instance, taken some money from your purse, would you call the police? I wouldn’t call the police but my child would be sanctioned in some way. If she takes things from others regularly or is in and out of trouble all the time ... well, that’s a whole different scenario again.
Sorry " that’s not much help really " I would advise talking to a close friend at home who knows your family and your daughter " the decision you make here could have huge consequences (yes, everyone should have consequences to their actions) " I don’t know the law, especially US law " if your kid has not been in any kind of trouble before, then I think it’s a big risk to take. Of course, if she hasn’t been in trouble before, then the law may just caution her or the family would not press charges and let it go.
Hopefully a legal expert may come along and let you know how the law would view this. If not, I would try and find out the legalities before going back to the parents and returning the item.
I hope you are able to resolve it and that your daughter will learn by her mistakes when you talk with her about this - and that the family have their item returned (tho insurance company would need to be notified) " but I do hope that the consequences of her actions a year ago will not affect the rest of her future adversely if the other family decide to press charges (if they can, don’t know the law).