Everyone knows the names. Kim, Khloé, Kourtney. Then you have Kendall and Kylie. It’s the ultimate reality TV dynasty, a billion-dollar web of Skims, Lip Kits, and endless Hulu seasons. But honestly, the family tree is way more tangled than what you see on a 42-minute episode of The Kardashians.
When people talk about the kim khloe kourtney half sister, they usually mean Kendall and Kylie Jenner. That makes sense. They grew up in the same house. They share the same mom, the legendary "momager" Kris Jenner. But if you’re looking at the actual biological reality, there’s another name that almost never makes the headlines: Cassandra "Casey" Marino.
The Hidden Jenner
Casey is the daughter of Caitlyn Jenner and her first wife, Chrystie Crownover. She was born in 1980. That makes her exactly the same age as Kim Kardashian. Think about that for a second. While Kim was becoming a global icon, her half-sister Casey was living a completely quiet, private life as an interior designer in California.
She isn't a "step" sister like the tabloids sometimes mess up. Because she shares a father with Kendall and Kylie, and Kendall and Kylie share a mother with Kim, Khloé, and Kourtney, Casey is part of this massive, interconnected web. But you won’t find her in the opening credits.
Why You Never See Her
It’s kinda wild to think about how different their lives are. Casey is married to Michael Marino and has three kids: Francesca, Isabella, and Luke. She’s famously private. While the Kardashian sisters are dealing with paparazzi at Nobu, Casey is reportedly busy with her family and her design work.
There was a big moment back in 2015 when Caitlyn transitioned. Most of the world was watching the 20/20 interview with Diane Sawyer. During that time, Caitlyn actually apologized to her first four children—Burt, Casey, Brandon, and Brody—for not being present enough during their childhood.
"I didn't do a good job. And I apologized to my kids for that." — Caitlyn Jenner
That's heavy. It explains a lot about why the older Jenner kids aren't exactly front-and-center on the reality shows. There was a lot of distance for a long time.
The "Other" Half Sisters: Kendall and Kylie
We have to talk about the ones you do know. Kendall and Kylie are the most famous examples of a kim khloe kourtney half sister. But even that dynamic is changing. In 2026, the sisters have been very vocal about how they hate the "half" label.
On a recent episode of her podcast, Khloe In Wonderland, Khloé Kardashian got really real about this. She basically said she finds it weird when people use the term "half-sister." To her, they’re just sisters. Period. They grew up together. Khloé was basically a second mom to Kendall and Kylie when they were babies.
The bond is clearly there, but the genetics are still what they are.
- Kourtney, Kim, Khloé, and Rob: Same mom (Kris), same dad (Robert Kardashian Sr.).
- Kendall and Kylie: Same mom (Kris), different dad (Caitlyn Jenner).
- Casey, Burt, Brandon, and Brody: Different mom, same dad (Caitlyn Jenner).
The 2026 Family Dynamic
So, where do things stand now? It’s complicated. If you follow the news, you know that Kris and Caitlyn don't really talk anymore. Caitlyn admitted in late 2023 that they have "no more contact," which is pretty sad considering they were married for over 20 years.
This tension usually trickles down. While Kendall and Kylie are obviously close to their dad, the Kardashian sisters—Kim, Kourtney, and Khloé—have a much more strained relationship with Caitlyn. This naturally affects how often they interact with the older Jenner half-siblings like Casey or Brandon.
However, there are still flashes of unity. Casey has hosted Caitlyn for Thanksgiving and Christmas recently. She seems to be the bridge in that specific part of the family. She doesn't need the cameras to have a relationship with her father.
What Most People Get Wrong
The biggest misconception is that there's some huge "feud" between the Kardashians and the "hidden" Jenner sisters. Honestly, it’s probably just lack of proximity. The older Jenner kids grew up in Malibu with their moms (Chrystie Scott and Linda Thompson). The Kardashians grew up in Calabasas.
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In a world where every move is calculated for "content," Casey Marino is a refreshing outlier. She’s the kim khloe kourtney half sister who chose a normal life.
Actionable Takeaways for Fans
If you're trying to keep the family tree straight, here is what you actually need to remember:
- Kendall and Kylie are the only sisters who share Kris Jenner as a mother with the Kardashians.
- Casey (Cassandra) Marino is the biological half-sister to Kendall and Kylie, making her part of the extended Kardashian circle, though they are not biologically related.
- Privacy is a choice. Casey's absence from the screen isn't a sign of a fight; it's a sign of a different lifestyle preference.
- Check the dads. Always look at the paternal side to understand why some siblings (like Brandon and Brody) show up occasionally while others never do.
If you want to understand the modern celebrity landscape, looking at the sisters who aren't famous is just as interesting as looking at the ones who are. It shows that even in the most public family in the world, you can still choose to stay in the shadows if you want to.