Visible crew/equipment: When Doug and Carrie leave for their holiday, a stage light is reflected on the kitchen door. (00:09:30)
Visible crew/equipment: At the end of the episode when Carrie and Doug are arguing about her letting him win a ping pong game, all the windows over the bed are closed, they leave the bedroom to go play a rematch, when they return to the bedroom Carrie starts pushing Doug down on the bed and the middle window is open, as they lay down further you can see someone swing the window shut. (00:27:00 - 00:28:00)
Visible crew/equipment: When Carrie walks in and sees Hollie for the first time in the episode, a boom mic can be seen following Carrie across the kitchen. (00:07:00)
Visible crew/equipment: When Carrie goes into the kitchen and Doug is seen through the window getting burnt, the boom's shadow can be seen moving along the wall by the window. (00:14:45)
Cheap Saks - S6-E15
Visible crew/equipment: While Doug reaches for the phone when Trish is calling you can see where the kitchen wall is ending on the set. (00:11:53)
Visible crew/equipment: When Deacon comes to get his camera, after he walks toward the back of the house, you can already see the shadow of the mailman in the doorway.
Tank Heaven - S6-E21
Visible crew/equipment: When Doug and Carrie close the door after saying bye to the first couple, you can see camera lights and a boom mic moving in and out reflected in the window behind them. (00:06:10)
Visible crew/equipment: When the camera cuts into the wide shot of Carrie leaving the store, the camera rig to the left of the screen is almost entirely visible. You can see it follow Carrie around for a good 10 seconds. (00:10:35)
Visible crew/equipment: When we see Arthur playing Shuttleboard for the first time, his mic pack is visible. (00:08:00)
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.