"Really looking forward to becoming a mumma with the support of our dear family and friends who already love him soo much!! I love you Hal ❣️," she signed off her message.
Her loving twin commented her support under the post.
"Weeeeeeee Aunty Mishy on stand by xxxx," she exclaimed.
Mish further celebrated the monumental moment by sharing a picture of a newspaper clip about her sister's pregnancy.
The headline read, "Oh boy! Former MAFS star having a baby."
She reacted, "Congrats @Shazzimarsh and Hal. I am going to be an Aunty to my first nephew."
Mish's former partner on MAFS, Jesse Konstantinoff, commented on Sharon's post his well wishes by sharing, "Massive congratulations ❤️💙."
One excited fan wrote, "So happy for you, babe! 💙💙💙," and another shared their glee, "❤️🥰 We're soo happy for you and Hal hun! 😊 so exciting! 😍 xxxxx."
The twins marked a world first for MAFS in 2017 when they had a double wedding.
Sharon wed Nick Furphy while Mish married Jesse, and the now expecting bride stayed with Nick briefly after the show. But they couldn't make it work even when Sharon moved to Melbourne to be with him.
Mish has also moved on from Jesse and is in a long-term relationship with Chris Sabel.
Want a fairytale love story of your own? For a limited time, enjoy 20% OFF an eHarmony subscription! Offer ends Aug 31, 2022.
This article first appeared on our sister site, Now to Love.