Hi! That’s an interesting situation. I would go out and get a few duplicate, cheap rings for her. Keep them all except one, and give that one to her. Say, “Mom! Look, I found your ring!” and just let her have it. I would recommend locking your bedroom door, if you can. Many people with dementia have a “one track mind,” and if she’s focused on that ring, it will only stop when she A.) gets a ring replacement or B.) forgets about it–but that could take a while!