Visible crew/equipment: When Susan sits on the couch in Edie's house, just after she throws the bra behind her and knocks the candles over, a crew member in blue jeans can be seen moving on the floor behind the couch to the right.
Visible crew/equipment: Just before the fire starts you can see a crew member's legs/feet on the right side of the couch. (00:38:06)
Visible crew/equipment: When Bree is watering the flowers in the bathroom at the hospital, a shadow of the cameraman is visible behind her.
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.