Audio problem: When the Stagehand says "Come on, you're up!" to Susan before she is about to go on the catwalk at Gabrielle's fashion show, the words do not match his lips.
Audio problem: When Susan is on the catwalk at Gabrielle's fashion show, Tom announces what she is wearing, but if you look in the background you can see his lips are not moving when he is speaking.
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.