Taste Buds - S5-E24
Other mistake: When Doug sits down to eat and Arthur touches his food, Doug says, "That's what my sandwich was missing, a finger with a loose bandaid on it," and pushes Arthur's hand away. When he does this you can see Arthur isn't wearing any bandaids on his hands. (00:00:05 - 00:01:00)
Other mistake: Carrie says that Deacon doesn't drink or smoke. Many episodes have shown Deacon drinking a beer or a margarita.
Other mistake: During the picnic softball scene, there are mountains in the distance. There are no mountains in or near Queens New York. (00:05:40)
Thanks Man - S6-E9
Other mistake: When Deacon's youngest son says "is that man going to freeze, daddy" you can see the older son mouthing the lines. (00:06:16)
Fresh Brood - S8-E12
Other mistake: When Danny comes in with the baby and says nothing about it, Doug says, "Gare, what's goin' on?" Danny is played by Kevin James' real brother Gary Valentine. (00:02:45)
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.