Okay so I'll make this short and to the point, I've moved in with my girlfriend and her 2 children 16 (boy) and 13(girl). I myself am a single father of a 13 yr old boy. my girlfriends daughter has been caught several times going through everyones rooms and on occasion helping herself to peoples stuff, whether it be food, money whatever. She was caught one time going through our bedroom drawers but was mildly punished with a grounding by her mother. recently she has been caught red handed stealing for the second time this week from my son's room, she walks in constantly and takes what ever she sees in his room, money being the last 2 times. I have done a quick once over in her room several times before when the other 2 lose things and 95% of the time it ends up in her room some how. This last time there was a few dollars on my son's floor and she wandered in and just took it..when I confronted her she just stares at me..she gave it back and admitted it but just stares at me when I ask why!? she has her own paper route and even walks the neighbors dog, she makes more $$ than the other 2 combined!! yet she has no problem taking things that aren't hers. Her mother sent her to her room for her last incident and talked to her but that was it, mild grounding...my son wants a lock on his door but she says no..what do I do? It's her house...but this can't go on! I've now had to lock my office all the time cause she comes home for lunch and is home alone during this time. advice? punishment ideas? anything?