No Orleans - S4-E16
Continuity mistake: When Spence is seen eating a snow cone for the first time, the level of it changes between shots. (00:06:10)
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)
Continuity mistake: When Carrie finds Doug in the kitchen in the middle of the night, her arms are crossed with her hands tucked into the sleeves. After she asks him about his pay check from IPS, the shot changes and her hands are now on her hips. (00:10:50)
Continuity mistake: When Doug is talking to Carrie in the kitchen about his ideas for the sandwich shop, lights reflecting in the living room windows behind Doug turn off and then back on when the shot changes between Doug and Carrie. (00:11:00 - 00:11:35)
Continuity mistake: While at Doug's high school reunion, he and Carrie are dancing. Carrie has her purse on her shoulder. When they go for a beverage, the purse is gone. She was able to put her bun back without having a purse swinging in her face.
Shrink Wrap - S4-E25
Continuity mistake: In the scene when the therapist asks Arthur to recall a specific incident about not being heard from his childhood, he is playing with his pen cap. The shot cuts and he is instantly holding his note pad with both hands. (01:35:40)
Continuity mistake: When Carrie is starting her new work position, her bag on the desk behind her moves without anyone touching it. (00:04:20)
Window Pain - S5-E2
Continuity mistake: When Carrie and Doug are having the discussion about the dry cleaning, the way Carrie is holding it changes instantly. (00:06:10)
Window Pain - S5-E2
Continuity mistake: When Doug and Carrie are arguing outside the neighbour's house, Doug takes a big swig from the Scotch bottle and then puts it on the ground. After the police pull up, the shot cuts back to Doug and Carrie. Doug picks up the bottle from the neighbour's porch railing. (00:42:45)
Continuity mistake: When Carrie starts praying in the bedroom, Doug has his hands together. Camera changes and he has got his watch in his hands. A watch that was not in his hands or on his wrist before, might I add. (00:09:50)
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.