"Vinny’s reaction.... When she says ‘we going to have our family now’... and then ‘Is it kicking yet’? My heart nearly exploded, So beautiful," Moana captioned the video.
"She couldn’t quite find all the words to express all of her excitement. But knowing she is going to be an Aunty is all she talks about. Every morning when we have coffee we literally count down the day."
According to Isabella, Vinny has been asking on a daily basis if the baby's kicking or if her bump is getting bigger - so sweet!
Moana became the sole carer for her disabled sister Vinnie at just 26-years-old. Vinnie has Moebius syndrome, a rare neurological condition affecting facial muscle and eye movement.
In an Ask Me Anything on Instagram, Isabella also revealed more about the conception, explaining that the couple tried two rounds of Intrauterine Insemination (IUI) with a sperm donor before trying IVF.
Though Isabella and Moana were successful on their first round of IVF, they acknowledged was "really lucky" and something they were thankful for.
"I learned so much about IVF from the whole process which I had no idea about what a massive journey it is to go on," Isabella admitted.
Moana and Isabella announced their pregnancy via Instagram with a trio of stunning images.
"I don’t yet have the words to fully explain how happy we are. It’s a dream come true for us and in November we get to meet our little person," Moana wrote in her caption.