There is no hard and fast law on how long you have to keep them. A common way to proceed is to send her a letter, sent some way or ways you can prove delivery, such as certified mail or FedEx with tracking, reiterating briefly what you have and your attempts to have her pick it up, then stating that if she does not have the materials retrieved within, say, 30 days, you will treat them as abandoned and disposes of them however you wish. If she doesn't get them after that, sell them, throw them out, etc.As to the paycheck: contact the state labor department and let them know about this--they can sometimes help employees get missing paychecks. If they can't or won't help you, sue for the check in small claims court, acting as your own attorney ("pro se") to save on legal fees. If the business is an LLC or corporation, sue the business; if it's not, sue the owner(s) personally.