They go through theirfair share of ups and downsjust like all siblings, butKourtney Kardashianwill always lean on her sisters.

The reality star, 40, just launched hernew lifestyle and wellness website POOSH— also her daughter Penelope’s nickname — and talked with PEOPLE about her business-savvy sisters before her chat with long-time friend Allison Statter during the closing panel ofCreate & Cultivate‘s empowering women entrepreneurs event in San Francisco over the weekend.

“[My favorite sister] changes every day.Today it’s Khloe. Yesterday it wasnotKhloe,” she quipped during their panel. “Yesterday it was Kim.”

Kourtney’s POOSH has included personal stories from her and her family, including younger sisterKim KardashianWest’s tips fordealing with her psoriasis.

“It’s knowing that we are there for each other,” Kourtney tells PEOPLE exclusively of herbond with her siblings. “It’s just that kind of unconditional support that you can’t find everywhere. I think we all respect what the other have done and we are always here for each other.”

Kendall, Kourtney, Khloé, Kylie and Kim.Khloe Kardashian/Instagram

Kendall Jenner, Kourtney Kardashian, Khloe Kardashian, Kim Kardashian West, Kylie Jenner

Although, going it alone can also be a confidence builder. When she invited her sisters to the POOSH launch party, they couldn’t attend due to photo shoots, theEmmy Awardsand travel schedules.

However, “we lean on each other for support,” she says. “I think doing such a successful event [with just my mom] made me stronger. It made me think, you know, that I could do it on my own.

“What feels authentic to me for a launch feels different to Kim, feels different to Kylie. So it’s nice to just have our own approaches,” she adds.

She says fans of her family’s showKeeping Up with the Kardashianswill feel right at home when they visit her website, and she hopes it inspires women to join in the conversation.

“I feel like it was a big thing for me to only take on something my heart and soul was really in,” she explains, adding that her team is “all women.”

“We have our meetings and it is all women, including two of my best friends from high school. I just find that very empowering and it’s also a place where you find understanding,” she says. “It may besomething to do with our kids, or things we are doing, it’s just nice to be able to talk about that at work.”

“I have a lot of close friends who are pastors from going to great churches, and I was interested in how to incorporate spirituality and my beliefs into my children’s lives because my dad did such a great job of it with us,” she says. “I don’t want to be forceful with them, I want them to have an understanding of spirituality.”

source: people.com