Fans of the couple left a number of love-heart emojis in the comments, with some sweet tidings to match as well.
“Merry Christmas beautiful fam ❤️❤️,” one penned.
“Hendrix is the image of his lovely Mum,” another commented.
“Awesome photos, wonderful memories and happy Christmas season to you four...,” another kind fan wrote.
This was the first Christmas for Hendrix, Jen’s youngest, who was born in October this year, not long before Jen turned 38.
“Welcome to the world our sweet boy,” Jen wrote, announcing Hendrix’s birth via Instagram.
What a week it’s been! Our little man wanted to say hello to the world earlier than expected and has needed some extra care but is now doing so well and is healthy and strong!!” she explained.
“We could not be more grateful or more in love!!”
Hendrix’s arrival came as the perfect early Christmas gift, not only giving Jen and Jake their first son, but giving Frankie a brother.
Frankie can be spotted in the Christmas snaps grinning at Hendrix.
Jen’s eldest daughter turned two just a matter of days before Hendrix arrived.
“My heart! Couldn’t love these lil ones more,” she wrote.
Jen’s gorgeous family didn’t come to her easily, with the Aussie beauty queen speaking candidly about her struggles with miscarriage before she had her two kids.
“I had so many years of planning, but the one thing I so dearly wanted couldn’t be planned,” she told Stellar in 2019.
“I felt like I almost broke and, in fact, it’s still really raw. But Jake was amazing. He let me sit with the pain, feel it, and not be OK,” she explained.
“With women, we want everything to be OK, but sometimes, it’s just not.”
WATCH: Jennifer Hawkins' daughter celebrates turning two