In this episode, the Duboises make such a big deal about Ariel being old enough to finally learn to drive. However, two episodes previously ("Things to Do in Phoenix When You're Dead") Ariel drove herself to school and Joe complimented her on her prowess.
In "Four dreams" the alternative Allison who doesn't have children looks at some kids in a restaurant and gets a dreamy look on her face. The mother of the children she is admiring addresses her daughter as "Sofia". The "real" Allison's daughter Ariel is played by actress Sofia Vassilieva.