Court Date - S1-E17
Revealing mistake: When Carrie kicks Doug Spence and Ritchie out the bedroom she shuts the door and the set wall wobbles very noticeably. (00:07:30)
Court Date - S1-E17
Continuity mistake: When Arthur storms out saying that was his drug speech, Carrie has her wrists in the table in one shot and under the table in the next. (00:15:10)
Court Date - S1-E17
Continuity mistake: When Doug, Carrie and Ritchie are talking about the cop having not called her yet, Doug's hands are either on or off the bottle of beer, and the level of beer/foam changes between shots too. (00:16:30)
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.