Get a new roomate, or get a safe ( a weed safe thats a good idea!). If all else fails confront her on it, but then again once a thief allways a thief, she'll just keep on doing it if you don't let her know that you know. Even then she'll proably still steal from ya, get her ass kicked out. or take a lesson from the AsianStoner420's thread and piss on her bed that will teach her! lol oh didn't realize Rebgirl suggested it too....