Rebel also took to Instagram to share photos of herself ahead of the gala dressed in a stunning frock by the Rene Ruiz Collection.
"I hope you feel as great as you look. Beautiful picture and dress," one proud fan wrote in the comments.
"You shimmery mermaid, if I catch you in my net, I’m keeping you," joked another.
"Damn you’re looking really good. Proud of you! Just be healthy. Don’t listen to Hollywood. You’re amazing and beautiful and ENOUGH exactly as you are," a third penned.
The new couple also posed on the red carpet at the gala event and Rebel shared her own snaps of herself and Jacob to her Instagram stories.
According to PEOPLE, Rebel and Jacob were introduced by a friend last year and struck up a romance while Rebel was in Australia and Jacob was across the seas in LA during quarantine. After Rebel landed back in the US, she and her new man reunited in California.
"They are officially boyfriend and girlfriend," a source told the publication.
"He's a gentleman, has very old school manners and treats her well. He is also very health conscious and they've been motivating each other with their health journeys."
Rebel's new boyfriend is also worth around US$100 million, with his family being the founders of the Anheuser-Busch brewing dynasty.
Back in May, Rebel revealed that she was "working hard" to achieve both her fitness and career goals, explaining that she's trying to get down to 75kg.
"Even if you have to crawl towards your goals, keep going, it will be worth it," she wrote in a motivating message on Instagram.
"Try and give a little bit of effort each day... I know some days are frustrating as hell, you feel like giving up, you get annoyed at the lack of progress... but good things are coming your way.
"What are your goals this year? I’ll be honest with you guys - with my 'Year of Health' mission I’m trying to get to 75kgs and career wise am trying to get one of my movies into production before the end of the year! Both of these things are requiring a daily effort and there’s constant set backs - but I’m working hard," she added.