In a new interview, she spills the secrets on famous trio Kourtney, Kim and Khloe's style. "I love how Kim is so fashionable," she said, speaking to Us Weekly.
"She has a look set for her vibe. She'll have the latest and greatest from every fashion designer, and we work around that."
Jen is also a fan of Khloe's edgier fashion sense. "I love how Khloe is so daring and will try things even if she's not sure," she said. "She's open to whatever. We'll pull inspiration pictures and go off of whatever wardrobe she's wearing."
As for eldest sister Kourtney, Jen loves her quirky edge. "Kourtney is electic but so on point," she added. "She's not afraid to wear a cool turban. So she's kind of a mixture of the two [other sisters]."
The girls often experiment with their hair colour and style – Kim recently went blonde and then dyed it back brunette, while Kourtney had a fringe put in earlier this year – but one style that Jen refuses to try out on them is short hair.
"I don't want to," she said. "I appreciate that all three of them love their long hair, and they're versatile with it.
"There've been moments with Khloe where we're like, 'Should we cut your hair into a bob?' And I'm like, 'You know what? No, because I know we'd be sick of it in two weeks.'"