But hand-in-hand with the positive comments came negative (read: unsolicited) feedback.
"She really needs to cut his hair," one follower chimed in.
The divisive comment didn't go unnoticed either, as Kardashian swiftly replied: "She really need to not worry about kids that aren't her own. He is a happy boy."
Her prompt comeback garnered 3,135 likes with fans rushing to defend the small screen star.
"Amen. His hair is gorgeous and I'm a little envious to be honest," one commented.
"Never cut his hair (unless he wants to)," a second user urged. "He is a long-haired beauty."
Although it's not the first time the 40-year-old has had to defend herself against mum-shaming social media comments.
The Keeping Up With The Kardashians star famously took her three children on holiday to Portofino, Italy in June. But when she posted a bikini-clad photograph of herself on a yacht, one follower replied: "Where are your kids?"
In response, she quipped: "My son was taking the photo, and the other two were sitting a table across from me. Thank you so much for your concern."
Despite the unanticipated furore over her latest Instagram snap, she received A-list support from friends including Bella Hadid who wrote: "This makes me so happy."
She isn't the only member of the Kardashian clan who knows how to stand her ground in the middle of a fiery social media debate either, as younger sister Kim recently came under fire for allowing her six-year-old daughter North West to wear supersized hoop earrings.
After posting the divisive photograph back in September, negative comments soon started rolling in.
"Cute but those giant hoops for a little girl? She’s not even 11 yet," one person wrote.
"OK, I never say anything bad regarding anyone's kids but North has no business wearing hoops that big at what, six? They're going to pull on her little holes," another added.
In the wise words of Kourtney, let's not "worry about kids that aren't our own".