Continuity mistake: When Doug talks about sleeping on his mitt, the way he holds it changes instantly. (00:00:45)
Continuity mistake: The door to the house is on a corner. However, in the interior shots, they have a window each side of the door.
Continuity mistake: When Carrie says that Doug is losing brain cells in the garage due to fumes, the way she holds the tickets changes instantly. (00:12:20)
Continuity mistake: At the start, when Carrie is talking to Arthur about being inseparable she has her jacket over her arm. Camera cuts and now she is putting it on instantly. (00:00:10)
Continuity mistake: At the end, the shawl around Carrie's shoulder is either covering her shoulder or not depending on the shot. (00:20:50)
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.