Appropriate punishment for 12 yr old daughter who stole her brother's sim card?

I would take away any electronices ~ computer, tv, cell phone, ipod, etc. She can use a computer in a general area in the house that can be easily monitored. I would also take the door off of her room and tell her that she doesn`t respect your rules so you won`t grant her any privacy. She can earn each and everything back by helping around the house. I wouldn`t set a time period to when she would get stuff back. If she has to earn back all of her things she will think twice about disobeying. I also know parents that took their daughter clothes away and they picked out her clothes to wear to school for the a few weeks. I guess it worked well for them... good luck.