The reality TV star, 44, was at a Lemme event inside Target.
The POOSH founder looked slender after welcoming her son Rocky Thirteen Barker only four months ago with husband Travis Barker.
Also at the event was her sister Khloe Kardashian, 39, who had on a pale lilac dress that made the most of her cleavage.
Also on hand in the store was momager Kris Jenner in black.
Kim Kardashian was not seen, not were Kylie and Kendall Jenner.
The camera people were also around to film for the family’s Hulu show The Kardashians.
Though Kourtney and Khloe have had nasty catfights in the past on their show as Kourtney bullied Khloe over and over again, they seemed like friends at the event as they hugged.
Last week Kourtney shared images to Instagram.
‘That’s life,’ she captioned the post, which featured her soaking in quality time with her family, rocking a pair of black Christian Louboutin heels and posing for a glamorous selfie.
The mother-of-four also included a precious image of Rocky’s hand holding the chain necklace around his dad’s neck.
Kardashian’s pictures appeared to be taken throughout the past month as she included a view of her staircase full of red roses on each step seemingly from Valentine’s Day.
A number of the Keeping Up With the Kardashians alum’s followers flocked to the comment section to praise her for a sharing a snap of her ‘real mum body.’
One fan gushed: ‘Love your pump shot! ‘
A third asked: ‘Who says pumping can’t be sexy?’
‘That’s my sister!!!’ her younger sibling, Khloé Kardashian gushed underneath the slideshow.
Others, however, ‘why’ she was sharing a photo of herself ‘pumping breast milk.’
‘It’s such a personal private intimate thing,’ one commentor inquired. ‘But I guess everyone sees it differently. God bless you and your family. Very happy for you all.’
Another critic wrote: ‘the pumping photo really??? smh [shaking my head].’
Her followers fiercely defended her against the small handful of trolling comments, with one stating ‘it’s a normal mom thing’ and that breastfeeding needs to be ‘normalized.’
Last month, Kardashian shared her postpartum tips on clothing, hair, make-up and breastfeeding.
‘Getting dressed postpartum while breastfeeding [equals] throwing on an oversized coat, flat shoes pretty much always,’ Kourtney wrote on her Instastory.
‘[I love] leggings, sweats – anything baggy and comfortable aka husband’s vintage T-shirts and Dickies. Anything super fast to throw on. [The] less time away from my baby the better.’
Kardashian then described her two-minute hair and make-up routine which included her half-sister Kylie Jenner’s $18 ‘High Gloss’ lip gloss, a dab of $30 Kosas ‘Revealer’ concealer, a lash curler, one coat of mascara, and an eyebrow brush.
The Kardashians producer-star lets her hair air dry ‘however it wants’ with no product: ‘[It] used to be super straight but after I [dyed] her blonde she’s got some texture.’
As for postpartum hair loss, Kourtney recommended fans use $40 Lemme ‘Mama’ from her vitamin and botanical supplement company.
‘So I took @lemme mama during my pregnancy and still take it daily postpartum and I haven’t noticed hair loss this time so far,’ Kardashian wrote.
‘I do take other supplements too (vitamin D/K, calcium/magnesium, omega 3, probiotics, iron, B complex).’
The Poosh founder also gave a long list of foods that might boost a nursing mother’s breast milk supply recommended by her nutritionist Leona West Fox.
