When DJ and Stephanie are plotting to lure Jesse and Joey into their room, a baby gate is propped up against the staircase. In the next shot, when Stephanie walks up the staircase, the gate has been removed.
DJ has a purple belt in karate, but is all wrong when she briefly demonstrates it. Her fists are not in any proper form, the open-hand move she did is non-existent, and all open-handed moves require the thumb to touching the rest of the hand instead of sticking out.