According to Fox News, Baena, who is Arnold Schwarzenegger's love child, was at the gym during the wedding.
The 21-year-old later attended the 'Vintage Hollywood 2019' party in Los Angeles while his 29-year-old half-sister partied with her new husband and close friends.
Katherine was previously trolled by her fans when she excluded her half brother from a National Siblings Day post on Instagram.
Katherine and Chris got hitched on Saturday at San Ysidro Ranch in Montecito, Calif., and the newly-married couple shared the first from their marriage on Sunday.
The couple simultaneously posted pictures on their respective Instagram accounts, in which Katherine can be seen walking hand-in-hand in a white wedding gown while Chris looked dapper in blue formals.
"Yesterday was the best day of our lives! We became husband and wife in front of God, our families and those we love. It was intimate, moving and emotional. We feel so blessed to begin this new chapter of our lives. We are so thankful to our families and our friends who stood with us and grateful to Mr Giorgio Armani who created a once in a lifetime dress for Katherine to wear and for me, the perfect suit. This morning we feel nothing but blessed," the duo wrote alongside the pictures.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)