Continuity mistake: Arthur gives Holly a book at the start and she has it in her right hand. Camera cuts and now it is in her left hand. (00:03:20)
Continuity mistake: In the establishing shot of the gold course, it's a bright and sunny day. A few moments later when they are all teeing off it's drizzling rain and you can see Doug's breath. (00:09:35 - 00:11:30)
Continuity mistake: When Carrie takes a drink from her cup of tea she is holding her cup with 1 hand in one shot and 2 in a second shot. (00:14:30)
Continuity mistake: When Carrie is talking to Tina about playing 3 holes, her hands are outstretched. Camera cuts and her gloved hand is now on her hip. (00:16:40)
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.