The TikTok star made her ballroom dancing debut during Monday night's Disney+ premiere, with her and partner Mark Ballas earning the highest score of the night for their cha-cha to a remix of "Savage" by Megan Thee Stallion.
When asked afterwards by reporters including PEOPLE about how Barker was feeling about it all, D'Amelio, 18, gushed about his support.
"He was very proud of me," she said. "He's never seen me dance before, so I think I was nervous, but he's always been so supportive."
The couple's relationship is still new. Rumors circulated in early June about their potential romance, a source confirming their status to PEOPLE later that month. "They're seeing each other, and it's early stages," said the insider.
Since then, the pair have gone more public together, attending Machine Gun Kelly's New York City concert together, and Michael Rubin's star-studded July 4th party in the Hamptons.
The social media sensation is not appearing alone on the competitive show, as she and her mother, Heidi D'Amelio, 50, are making history as the first mother-daughter pair to star alongside each other.
On Monday night, Charli said she was "super proud" of her mom's performance and excited about the support in the audience. "I have really good friends and family around me, and I'm very happy that everyone came tonight to support me and my mom," she shared. "And that meant a lot to us."
Never miss a story — sign up for PEOPLE's free daily newsletter to stay up to date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
And though the duo are supporting each other, mom Heidi said the competition is still fierce within the family.
"We love each other. But she wants to win. I want to win," Heidi told PEOPLE before the show's premiere. "But at the end of the day, there can only be one winner."
Dancing with the Stars airs Mondays at 8 p.m. ET/5 p.m. PT on Disney+.