Sia has mentioned Christina on her blog.

christina is still amazing as ever,i call her the mad scientist,and oh,how we laugh.the songs are shaping up beautifully,and i’m super proud of us.i seriously want to chomp on her kid like he’s corn on the cob. holy cuteness. today at the studio we learned about…..

hot spots,a common dog ailment,hydrogen peroxide (be sure to dilute when using for ANYTHING),the spelling and pronunciation of temperament (befuddling),the beauty of the tv show House,the joy of mid afternoon milkshakes prepared by lance,with a cherry on top no less and finally, that according to sam,it’s never an inappropriate time to shout ‘sexwee!’ at a multi-platinum-selling artist. 

“We went in with no expectations; the whole thing was a massive surprise,” explains Wu. “But it was incredible. She was so musically talented, a vocalist who really knows her voice. The first takes sounded really amazing, and while we’d made demos, it was only when her voice was on them that it all came to life. It’s nice to talk about them, we’ve been sitting on this for a while!”