I'm confused as to why the lockbox is your concern. Why aren't you filing formal complaints?

I've dug around, and can't find anything pertaining to lockboxes and tampering, but I would expect that she could demand that you pay for replacing it if she knows that you were the one who tampered with it. Given the acrimony between you at the moment, it wouldn't be hard for her to figure out.

Nevermind the lockbox, protect yourselves and file those formal complaints.