I'm sorry it's giving you anxiety. Could you check-in with your sister and just let her know you were happy you could help her with a loan in her time of need, but you do want her to know you're feeling some anxiety so to please stay in communication about the loan and the expected pay-off date? I also think, I mean if it ever does go to court, if you have in writing follow-up, it wouldn't hurt to show that to the court too. Although hopefully your sister will understand that it's natural anxiety to have, but that you do trust her, and just want to be in communication so there's no surprises.