"Stephanie [Shepherd] wanted to transition into a larger role with Kim [Kardashian West]'s brand and businesses, it just didn't work," a source tells PEOPLE

Kim Kardashian West is without her longtime right-hand girl.

The 37-year-old reality star has opted to professionally part ways with Stephanie Shepherd, her friend and assistant since 2013, a source close to the Kardashian family tells PEOPLE.

“Kim made a decision to let Stephanie go,” the insider says. “She was a good assistant but when Stephanie wanted to transition into a larger role with Kim’s brand and businesses, it just didn’t work. Kim gave her the chance but after a short period of time it became clear that Stephanie just didn’t have the knowledge to take on a role like that. Kim made an executive decision to part ways.”

The source adds, “She’s still friendly with the other sisters but she and Kim aren’t really speaking.”

Stephanie Shepherd and Kim Kardashian
| Credit: Source: Kim Kardashian/Instagram

Shepherd told Refinery 29 earlier this year that Kim, who will be welcoming her third childanother girl! — with husband Kanye West via surrogate soon, conducted her interview makeup-free and in sweats. She began her position right before North West was born in June 2013.

Credit: Stefanie Keenan/Getty Images

“I was doing her whole schedule, doing her laundry, booking travel, putting the stroller together and all of these things. But I wasn’t nervous. I was just excited, always staying longer than I needed because I was trying to prove myself — and then North came early! I was a brand new assistant who had no idea what to do with a baby, but we all moved into Kris’ house, and she was the one who made it all feel okay and moved mountains for us,” Shepherd recalled to the outlet.

In a recent episode of Keeping Up With the Kardashians, Kim questioned Shepherd’s close relationship with her sister Kourtney Kardashian.

“Do you find it weird that you’re like ‘wifey’ with my assistant?” Kim asked, leading Kourtney ask her sister, instead, if it bothered her.

“Kind of,” Kim responded. “What if all of a sudden I became BFF with Megan? I think you would definitely be like, ‘That’s weird.’ ”

Kourtney, 38, also revealed that Shepherd confided in her about her job during their night out.

“Just a heads up, we were talking and she was saying that she didn’t know what she wanted to do in life,” the eldest Kardashian sister shared. “She feels, like, maybe she’s in a place in life where she’s unfulfilled, job-wise.”

She added, “I feel like she’s just looking to, like, evolve.”

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Although she was visibly shocked, Kim agreed that Shepherd had taken a step back in tasks such as styling. However, she said she has been given other opportunities, like helping to run the reality star’s Kimoji app.

“But I do think it’s like inappropriate for her to talk to you and not to me,” Kim said. “I mean don’t you think that’s like a little bit unprofessional?”

“Kourtney and I weren’t really close at all when I first started working, I don’t think she really liked me at first to be honest!” Shepherd confessed during her Refinery 29 profile. “When we were doing that world tour of Miami and Iceland and all those places, with so much travel time, we bonded. Now we talk all the time and we’ll go to dinner, or I’ll spend the night at her house. People always think we’re either lesbians, because we’re always together or holding hands, or that I am Kourtney, I guess because we look alike and have a similar style.”