Party Favor - S2-E13
Visible crew/equipment: When Doug goes back to the house after unsuccessfully scraping the frost off the car, a stage light is reflected in the window to the right of the front door. As Doug approaches the door his own shadow passes over this reflection. (00:01:30)
Party Favor - S2-E13
Visible crew/equipment: When Doug and Carrie are arguing about Danny coming over, you can see a stage light (not on) through the door window. We can also the neighbours garage, which we know from many outside shots of the Heffernan's backyard, is not that close to the house. (00:01:50)
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.