Factual error: It is very obvious throughout the whole episode that the mountain scenery is that of California wilderness...the trees, plants and mountains look nothing like those in New York or the East Coast.
Continuity mistake: At the start, the distance the canoe has drifted changes instantly. And it changes a huge distance. (00:04:20)
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.