Christie Brinkley and Her Kids Talk About the Personality Traits They All Share

Just what qualities do Christie Brinkley‘s kids say they got from their mom?

Musician Alexa Ray Joel, 31, actor Jack Brinkley Cook, 21, and model Sailor Brinkley Cook, 18 think they inherited her showbiz instincts. “It’s a contagious gene,” says Alexa in PEOPLE’s World’s Most Beautiful issue. “We’re all kind of theatrical and dramatic in different ways.”

• Watch the full episode of World’s Most Beautiful: My Beautiful Family now on the new People/Entertainment Weekly Network (PEN). Go to PEOPLE.com/PEN or download the PEN app on your favorite device.

But even though they have their differences — Alexa says she’s an “indoor girl” in a family of “outgoing blondes” and Jack calls Sailor “edgy “— “Everybody’s spirit is the same,” says the 63-year-old Brinkley.

“I think that the main thing I got from my mom was a sense of adventure,” says Jack. “Probably my favorite thing in the world is the ocean. I surf, I sail, I swim. Whatever it is, everything that has to do with the ocean, I’ve learned from her so I think that’s something I’ve gained from her because she loves the ocean, too.”

“We definitely keep each other humble — we tease each other,” says Alexa. “It’s very grounding to be with my family,”

Her daughters have learned a few key lessons from their mother, who they just posed alongside for the Sports Illustrated Swimsuit issue. “I just want to say something that makes my mom a really precious soul, very tender soul, is that she sees the beauty in everything,” says Alexa. “[She has] an endless zest and vivaciousness for life, like endless! She’s never tired. It amazes me because I never see her sleeping that much. But for some reason, she awakes perfectly refreshed and jubilant and little slice of sunshine… She sees the good and the beauty and the art in everything. She sees hearts in the clouds and things that people wouldn’t normally notice.”

Sailor says of her mom, “She’s never acted like a diva. And to me, that’s very very important. I’ve worked with a lot of people, other models, who have just not appreciated where they are or and who they’re with and what they’re creating, how much work goes into everything. I try to be appreciative.”

That’s one of the biggest lessons Brinkley wants to impart on her children. “I taught my kids, wherever you are, there’s something to be grateful for,” she says. “Gratitude is the key to a happy life.”