“I could barely walk that day and literally cancelled my flight three hours before,” the Kiss Kiss singer said.
“It was a bit devastating,” she added.
However, Holly has plans to see Olympia very soon, even if she’s unable to fly home.
“I’m trying to make it up for her, I’m crashing her honeymoon in about two weeks.”
And since the interview was pre-recorded, it was no surprise to see Holly pop up on Olympia’s socials overnight, joining her in Greece with her new husband.
“She did look beautiful, and I’ve caught up with her since her wedding and she is the happiest little munchkin on the planet,” Holly told the breakfast program.
“I’m very happy for her … I’ve never seen a more beautiful bride.
“And I’ve never met Thomas! I have to go meet my new bro,” she added.
Despite the 10-year age gap between the half-sisters, they seem very close, and both starred on Neighbours as they were kicking off their respective acting careers.
Both had cameos in the finale, which aired on July 28.
While Holly mostly lives her life outside the spotlight, excited fans were happy to see her return to the show, and even do press afterwards, opening up about her life in London.
Since stepping back from performing, Holly has married luxury property developer Nick Candy, and the two share two children.
WATCH: Olympia Valance's Neighbours Q&A