Train Wreck - S1-E20
Continuity mistake: When Carrie turns up at IPS, she holds out the coloured char with two hands then one depending on the shot. (00:09:50)
Train Wreck - S1-E20
Continuity mistake: When Ritchie is pretending to be Carrie, Doug has hold of his cue with both hands. Camera cuts and he's not holding the tip any more. (00:06:05)
Train Wreck - S1-E20
Visible crew/equipment: When Carrie grabs the mail off the floor if you look in the window behind her you can see the pole of a boom mic moving around. (00:12:45)
Train Wreck - S1-E20
Revealing mistake: Shari from ISP radios Doug about the rush order pickup at 1202 Stratford, so Doug pulls over and soon Carrie pulls him to the back of the truck. Cut to exterior shot of the truck, and the street sign reads "Lafayette, Culver City" which reveals the California location. The truck is parked on Culver Blvd, corner of Lafayette, in front of the well known Washington Building (awnings are now black), which is located a few blocks up from Sony Pictures Studios where King of Queens was filmed. (00:21:35)
Train Wreck - S1-E20
Visible crew/equipment: At IPS, while Doug gives his speech about using heavy package stickers, in the shots facing the drivers seated at the table, the end of the IPS set and a crew member are visible at the right side of the screen. (00:08:45)
Train Wreck - S1-E20
Continuity mistake: When Doug sees Arthur's headstone in the yard, the dark opaque flap of the dog door is missing from its frame, but it reappears as Doug enters the kitchen. (00:06:40)
Train Wreck - S1-E20
Visible crew/equipment: When Arthur asks Doug for help with the epitaph, the green and red tape markers are visible on the floor in front of the dishwasher, where Doug stands. (00:12:00)
Train Wreck - S1-E20
Continuity mistake: When Arthur is rewriting his epitaph, the pad and pencil keep moving between shots. (00:12:10)
Train Wreck - S1-E20
Continuity mistake: When Julie goes to get her jacket, Doug's board swaps hands instantly. (00:03:40)
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.