The Vampire Diaries 3X6: Smells Like Teen Spirit

Alright, so we've got evil Stefan who has decided he's got to go back to school since Klaus has entrusted him to keep tabs on Elena. The gang decides it's best if we capture Stefan and keep him locked up for the time being. Everyone is getting chores and when Tyler is given the job of obtaining the vervain to knock him out, he refuses, as Klaus would like agree to this plan. Damon quickly realizes he's been sired by Klaus and is now doing his bidding. He knocks him out and they drag him away to deal with later.

At the bonfire party, Elena 'pretends' to be drunk (I'm not sure how much pretending she was doing) to lure Stefan away, while Damon (much to Elena's jealously) is busy flirting with Rebekah to keep her occupied. Eventually, Elena falls off the bleachers and Stefan vampire runs over to catch her. When he does, and his back is turned, Alaric shoots him with some vervain. They drag him over to Alaric's car and toss him inside with Elena.

However, while this has been going on, Matt did a spell to be able to bring Vikki back. But, in order to balance the scales, she was tasked with killing Elena. She knocks Matt out, and heads over to light the car on fire, you know, the one Elena and Stefan are currently in. Elena tries to break out and Alaric tries to break in, but to no avail. Eventually, Elena wakes Stefan and he's strong enough to kick out the back windshield. Alaric helps Elena out and she insists they go back for Stefan.

Later, Stefan asked why she went back for him. And she tells him that she still believes he can be saved, but he calls her naive (or something along those lines). She disagrees, claiming it makes her strong.

Katherine has given enough blood to Mikael to get him to wake up, but he begs her to stop claiming he doesn't drink human blood. Once she unchains him and asks him what he eats, he grabs her and begins to feed on her.

Okay, I have a question though. Rebekah is apparently living in the boarding house now. Wasn't the whole point of putting it in Elena's name so she would have to be able to invite vampires in? Why can she just waltz in the door? Is it because she's an original? Some other reason? Or is this just a plot hole I'm supposed to overlook?