Rachel Bilson Cheers on Former 'O.C.' Co-Star Mischa Barton on 'DWTS'!
“Got to give it up for @mischamazing takes balls. Get it guurrrrlll! ❤️” the 34-year-old actress wrote on her Instagram, along with a photo of Mischa and her pro partner Artem Chigvintsev on her TV screen.
Also pictured inside: Rachel out to lunch that same day in Studio City, Calif.