Adding the hashtag "#comeback", the new mum told her 11 million followers being given the all-clear from her doctor and physiotherapist to do light workouts had helped her to get out of bed every morning.
But some mums have slammed the 27-year-old trainer for not sharing "honest" post birth journey photos.
"These kind of pictures are exactly the kind that makes women hate their bodies," one follower commented.
"Most of women can never get your body because of genetics, no matter how much dieting or exercise they do. Having perfect abs a couple of weeks after baby is also extremely rare."
While another woman said with an account following of nearly 12 million she wished Kayla would post more a "raw and honest journey" of her post pregnancy experience.
"Very disappointing and you're just adding to the unnecessary pressure from social media for new mums to look like yourself just a few weeks after birth," the woman added, before comparing her to fellow fitness star Tiffany Hall.
"Tiff Hall's, post pregnancy journey was much more raw and honest and therefore admirable. "It's disappointing you didn't take this route being a global figure that women look up to."
But not everyone shared those views with many women rallying in defence of the Bikini Body Guides co-creator.
"Some of these comments from women body shaming can we please stop and be a community of women that supports one enough instead of shaming because of a person's weight," one woman posted. "Everyone is different and fit strong looks different on everyone because not every one has the same body shape genetics etc."
Others thanked her for being an inspiration and commended her on posting post pregnancy modified workouts.
"Always such an inspiration, thank you for sharing your positivity with us," one woman said.
"New mum motivation is the BEST!!!! Keep shining bright beautiful mama," added another.
"Awesome!! You are such an inspiration to us mamas," commented a third person.
Kayla has been very vocal about her stance on body shaming, particularly after giving birth where she was slammed again over her weekly post-partum snaps.
"To be clear, I'm not posting these as 'transformations posts', nor am I concerned with my weight loss post pregnancy," she said of a post showing her at one week to two weeks apart.
"I'm simply showing you my journey, which many of the #BBGcommunity have asked to see."
However, some followers didn't agree, saying it wasn't an "uplifting" post.
"I am all for supporting women but I don't think it's uplifting to post something that focuses on your thinness after two or three weeks after giving birth," one woman had commented on the Instagram photo.
The renowned fitness blogger explained every woman's journey through life especially pregnancy, birth and healing post-birth, is unique.
She said regardless of how her body healed post-birth, she felt it was important to embrace, appreciate and celebrate her body.
In her most recent comeback snap, Kayla explained she is feeling very motivated.
"Because for me, fitness is my self care, my time out and my PASSION. Being able to share my passion with YOU, the #BBGCommunity is helping me to get out of bed every morning (not forgetting my incredible family)!! #comeback."
News.com.au has contacted Kayla for comment.
