Laura Byrne, Renae Ayris, and Juliette Herrera were also among those to congratulate the newly-engaged couple on their newest family member.
"What a beauty," 2018 Bachelor winner Laura wrote, while Renae added, "Oh my gosh!" with heart-eyes emojis.
The introduction of the four-legged family member may prove to be a trial run for the couple, with Irena revealing last year that she's got babies on the mind.
"I am so clucky already!" Irena told her Instagram followers when asked if she would ever consider having a baby.
"I can't wait to be a mum, it's something that I’ve always looked forward to," she added.
Irena also revealed that while she certainly hopes to had children with her future husband, she's still apprehensive after suffering a miscarriage last year.
"During our first few months together I, unfortunately, suffered a miscarriage,” Irena told WHO at the time. "But Locky was my absolute rock and having his support made me love him even more."
"We are just normal people and while we put ourselves in the spotlight, you never know what is going on in our lives that day," Locky added.
For now, however, Locky and Irena seem to be happy as they play mum and dad to gorgeous Odin and prepare to tie the knot after announcing their engagement earlier this year.
Speaking exclusively to WHO, Locky revealed he popped the question in Irena's home state of Victoria during a hike at Mackenzie Falls in the Grampians.
"When we reached the base of the waterfall I set up the camera to capture some photos of us but instead I hit the record button," the 2020 Bachelor said.
"Irena was standing in front of the waterfall for what she thought was a photo when I got down on my knee and asked her to marry me. It was absolutely perfect. Waterfalls and hiking are so us, so it was only fitting that I proposed at the waterfall."
WATCH: The Bachelor's Locky and Irena make surprise Celebrity Apprentice cameo
"Irena was in shock, she thought I was joking as I have done so many times before but then when she saw the ring she knew it was genuine this time," Locky revealed.
"She was blown away, couldn’t wipe the smile off her face."
As for what their wedding celebrations will entail, Locky revealed, "As Irena is from the East Coast and I am from the West, we hope to have two big engagement parties first with all our family and friends then hopefully a more intimate getaway wedding," the adventure travel guide says, though he admits the destination isn't sorted just yet.
"We will definitely be incorporating Irena’s Macedonian and Croatian traditions into the engagement and wedding as I have loved experiencing all the traditions and customs," Locky added.