Continuity mistake: The box of Sgt Salty cereal alternates from open to closed between shots when Doug and Carrie are talking. (00:13:30)
Continuity mistake: After trying the Sgt. Salty cereal, while talking to Carrie, Doug gets out a plate to make something else to eat. After he puts the plate down on the table, the cereal box moves and switches sides. (00:13:30)
Continuity mistake: Near the end when the Heffernans, Palmers, and "Shmenkmans" are having dinner and are in conversation, Carrie is shown sitting extremely close to Abby, who is on Carrie's left. But in shots in the middle of the conversation, there is significant empty space to Carrie's left.

Continuity mistake: When Doug and Arthur sit down to eat, the cup that is on the table is either by Arthur or by Doug depending on the shot. (00:06:35)

Continuity mistake: At the buffet, the cup that is on the table is either on or off a saucer depending on the shot. (00:06:55)
Continuity mistake: When Arthur's friend Mr. Glassman comes into the Heffernan house, a large tree can be seen on the front lawn, which we know from many other episodes there is not a large tree in front of the Heffernan house. (00:09:30)
Continuity mistake: When Doug is going into the living room after Carrie has gone in search of Arthur, his left hand is on the door. When he goes through the door, he is opening it with his right hand. (00:14:00)
Continuity mistake: Doug and Carrie are fighting in the kitchen. Around the time that Carrie says, "I give you one thing and you screw it up," Carrie's handbag in the background is standing upright. The shot goes back to Doug. When it goes back to Carrie and she is leaving, she picks up her handbag which is now no longer upright. Her handbag also looks like it has been shifted.

Wild Cards - S2-E20
Continuity mistake: When Deacon is sat on the bed with all the poker chips, the position of the chips on the bed is constantly changing between shots. (00:14:00)

Wild Cards - S2-E20
Continuity mistake: When Doug calls Carrie to confess, note the phone cable. The loop changes between several shots from a neat loop to an extremely messy loop. (00:20:30)
Soft Touch - S2-E22
Continuity mistake: At the start, when Carrie is trying to park, the same clip is shown. The same people walk by. (00:00:30)

Soft Touch - S2-E22
Continuity mistake: At the beginning, when Carrie is trying to park the car she's wearing a 3/4 sleeve blue top in the closeups, but in the overhead shot of the car for the last attempt when Carrie says that she's cutting it, the driver is not wearing that blue top, the driver is wearing a plaid shirt. (00:01:00)
Soft Touch - S2-E22
Continuity mistake: When Carrie is asking Doug why he likes it at the neighbors, her arms are on her hips. Camera cuts and now they are straight down at her side. (00:08:40)
Soft Touch - S2-E22
Continuity mistake: When Doug and Carrie are arguing about selling filters, the bed covers keep changing place. Note the position in regard to the jeans. (00:09:05)
Soft Touch - S2-E22
Continuity mistake: When Doug is getting into bed while talking to Carrie about selling water filters, his grip on the duvet changes instantly. (00:10:00)
Soft Touch - S2-E22
Continuity mistake: When Doug is asking Carrie about the water, she puts a glass down and the level of water in both glasses is significantly different. Camera cuts and they are level. (00:11:10)
Soft Touch - S2-E22
Continuity mistake: When Doug is telling Arthur about the filters, there is a leaflet on the table. Between camera cuts, this leaflet is constantly changing position. (00:13:25)

Soft Touch - S2-E22
Continuity mistake: When Arthur is trying to get Mickey to take a sip of water, Mickey crosses his arms. When the shot changes back to Mickey, he crosses his arms again. (00:15:30)
Soft Touch - S2-E22
Continuity mistake: When Doug is desperately trying to sell filters at IPS, he drops four boxes. When he picks them up, the position of one box in his right hand is constantly changing. Blue picture is facing the camera, but when the camera cuts, now Writting is facing where the camera was. Doug has not moved in this time. (00:17:55)
Soft Touch - S2-E22
Continuity mistake: At the end when Carrie is telling Doug not to take any more shots, she has one hand on Doug's arm. Camera cuts and she now has two hands on his arm. (00:19:25)
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.