Visible crew/equipment: When Doug says about Carrie's laugh he sits down on the sofa. As he does, part of the set lights are visible above him. (00:15:20)
Visible crew/equipment: When the dummy is on the sofa with Arthur, the stage lights are reflected in its sunglasses. (00:16:00)
Visible crew/equipment: When Arthur is saying about how someone should be able to go out their house and turn left or right, he looks up and the top of the set and the set lights are visible in his glasses. (00:02:45)
Answer: Sara hasn't been mentioned in later episodes, and it suggested in later episodes that she never existed, and that Carrie is an only child. Kevin James stated that the producers couldn't think of an good plots to use with Sara, so they left her out.