Character mistake: When Bree calls the police when she hears a noise downstairs, she says she lives at 4355 Wisteria Lane when her address is in fact 4354 Wisteria Lane. 4355 is the Scavo residence, not the Van De Kamp residence.
Secrets That I Never Want to Know - S8-E1
Character mistake: When Gabby and Bree go to move Gabby's stepfather's car, they realise his car is a stick shift and Gabby says that she has driven a stick shift only once in high school. This is incorrect, as in season 7 episode 8, Gabby has to drive Hector's car home, which was also a stick.
Answer: Kayla was sent away in episode 16 (The Gun Song) in season 4, after falsely accusing Lynette of child abuse. She now lives with her grandparents - probably Nora's parents.
I'm curious why we never see her again, why she never talked about, and why Tom never mentions visiting her.