My SD has over the last few months been "borrowing" things from my DD but this weekend was the final straw she borrowed her Pandora bracelet and has lost it when she was out with friends, we searched everywhere she's been but it's gone. This is a precious to my DD as once of the charms was given to her by my mum who passed away on the 24th October this year. My DD is devastated and hates her at the moment, normally my SD will borrow things and we find them in her room but this time shes gone too far, my OH has offered to get her a new one and all her charms back and has grounded my SD for a month no TV phone nothing she has to be straight in for school, which to be honest there isn't a lot more he could do. She said she took it because DD gets more than her which isn't true I recently bought them both Pandora rings for doing really well at school tests (I promised I would if they got above their set grades) they both got a lot higher than their set grades. My SD said that it's because I left her out when we recently went to a concert, she was invited but only decided the night before she wanted to come and the tickets had all gone but this was planned months ago and she kept saying she didn't want to come. I have now put a lock on my daughters door but OH said I should take it off I am refusing, he said that no bedroom doors should have locks but I disagree if it keeps DD stuff safe then it's staying, he is arguing that SD has learnt her lesson but it was always petty stuff before but she knew what the bracelet meant to DD, am I wrong in this?