Her announcement included a carousel of photos of her and Jonathan on what looks like a romantic dinner date, where he popped the question with a stunning ring.
Charlene and Jonathan have been together for almost a year, where they went public in January 2021 after three or four months of dating.
The pair met on dating app Bumble, and also moved in together this year, where Charlene shared a photo of herself and Jonathan in front of a removalist truck and said: "Moving day phase 1!!!!! Smashing it out like dynamite."
Speaking to 9Entertainment earlier this year, Charlene explained that the two are on the same page in terms of growing their family, and are both wanting to have kids together.
"I always wanted to have children, and then, obviously, I hadn't met anybody at that time. I wanted a career, so I just had planned that in a few years I would do that [have children] on my own if I haven't met anybody," she said. "But now I've met somebody."
She also gushed about Jonathan and said the two "understand each other at every level", and that he is "The One".
"Which is pretty amazing. I'm a happy lady," she said.
Charlene was partnered with Patrick on Married At First Sight, and while they stayed strong until final vows, the pair didn't last outside of the experiment.
Instead of forming a romantic connection, the two found they were better off as friends, and went their seperate ways after the show wrapped up.
"That marks the end to a truly amazing once in a lifetime experience!! @pattymiller_mafs we did so well, what an amazing team we were! Thank you for this incredible ride - looking forward to a lifetime of friendship," Charlene said at the time.