Continuity mistake: When Diane falls in the pool, the distance to the floating corpse on the left increases or decreases randomly depending on the shot.
Continuity mistake: After Carol slides through the kitchen floor, Steve rests with his back against the wall, over a brown line. When the angle changes, a frame later, he's resting half a meter to the right of the line.
Continuity mistake: While Diane faces the creature and demands it not to touch her babies, she is resting against a long flat wall, but from the angle behind, half of her body is resting against a corner.
Continuity mistake: The night the clown attacks Robbie, when he turns off the light the lamp and the Darth Vader bust swap positions between shots.
Continuity mistake: Before the clown attack, its left leg keeps changing positions between shots.
Continuity mistake: The night after burying the bird, Robbie's hat is not tucked in, however a frame later it's totally tucked in.
Answer: It seems that the majority of the activity was focusing in on the Freeling house exclusively. It's not fully explained why they were the only house affected, but there are a number of possibilities. Possibly because it's where the highest concentration of spirits were at unrest. Possibly because it could be inferred that the Freelings moved in first given Steven was involved with the company that built the community, and thus they became the first targets. And possibly because they were trying to get to Carol-Anne since she was an easy target.
Also, it is mentioned in the movie that Carol Anne was actually born in the house. That likely caused everything to focus on her.
It was not meant that Carol Anne was literally born inside the house, just while the family was living there. It was just a casual colloquial expression Steven's boss made.
raywest ★