Sisters Nicky and Paris Hilton have always been tight, but becoming parents together has strengthened their connection even more. Nicky, 40, shares Lily-Grace, 7, Teddy, 6, and Chasen, 23 months, with husband James Rothschild, while Paris, 43, shares Phoenix, 16 months, and London, 6 months, with husband Carter Reum. “It’s fun to have that bond and to get all the cousins together,” says Nicky. (Their younger brother, Barron II, 34, and his wife, Tessa, are parents to Milou, 4, Caspian, 20 months, and Apollo, 2 months.) “We are very, very close,” Nicky says of her famous family, crediting their Real Housewives of Beverly Hills alum mom, Kathy, 65. “That’s just how we were brought up.” Here, the fashion designer talks in Life & Style’s Lindsay Hoffman about trading parenting advice with Paris, her new Nicky Hilton x French Sole shoe collection and her go-to karaoke song.

The Hilton brood is growing! What’s it like being a parent alongside your siblings?

NH: Our group texts are very different these days, I’ll say that! We give each other advice on small things, like our favorite bottles, diapers, baby wipes, baby snacks. It’s great.

Your brother had his third child in March. How did you celebrate? 

NH: When someone welcomes a new baby, I always like to give them some space. I know from when I first had my children that you want that special alone bonding time.

How has becoming parents affected your relationships?

NH: The kids are included in everything. We do everything together. And I would have it no other way.

Is this how you envisioned your life to be?

NH: I always knew I wanted a family. I’m so lucky I get to do it with my siblings. The new generation of cousins is very sweet.

How have you managed to stay so grounded despite your fame?

NH: It’s knowing what’s important and what’s now. I have great family and great friends, and I hold those relationships dear to me and tune out any negativity.

How did becoming a mom change you?

NH: Having children has taught me a lot about patience and keeping your cool and not sweating the small stuff.

Would you let your kids go into showbiz?

NH: It’s very important to let your kids make choices and make mistakes. I plan to always be supportive within reason.

Congrats on your new shoe collection! What’s your footwear of choice?

NH: I’m a ballerina flat addict. They’re the perfect combination of comfort and elegance. I live in New York City, so I’m running around uptown, downtown, doing pickup, drop-off, meetings, hopping on and off the subway… It’s just the most practical footwear. Chic, elegant and timeless.

Where do you see yourself in five years?

NH: My mom and I are working on some projects together, which we’ll be announcing in the coming months. That’s really exciting. She’s my best friend, but we’ve never worked together professionally. We have very similar tastes, so it’s going to be fabulous!