This is the mother of two's second Halloween costume. On Friday night, Clarkson dressed up as Sia
and performed "Chandelier" on Facebook Live. "Welcome! Hey, what's up? I'm Sia this Halloween. What?!" she announced. "She's one of my favorites, so I thought I'd wear a wig and be Sia. I'm gonna cover a Sia song right here real quick, and I'm gonna talk to you."