Hi Def-Jam - S3-E13
Other mistake: When playing poker, Stef says she has all hearts which is a flush. However if you look at the cards she puts on the table, there is a 6 of diamonds and 3 of clubs. Therefore, not a flush. Everyone at the table, (Lou, Mr. Prezants, Deacon, Spencer and Doug) all agree it's a flush. (00:13:30)
Strike One - S3-E5
Other mistake: The salesman calls Doug by his name without Doug telling him his name. His Work ID as shown in other episodes states D. Heffernan. (00:07:20)
Strike One - S3-E5
Other mistake: When Carrie yells at Doug for ruining the bathroom, she yells when she is at the top of the staircase, and we can still see her legs. There is no way she could see the problems in the bathtub from there. (00:15:20)
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.