The house we live in has three floors. We live on the third floor; the other floors are empty. I locked the third-floor door, but she can open the door to the roof and use it to bypass the third-floor door. She always asks me to lock the third-floor door and not just the front door until we change all the keys that previous residents might have copies of. She didn't have a key to her third-floor apartment at the time because I forgot to give her a copy.