Maria Shriver and Katherine Schwarzenegger Share What Keeps Them Feeling Beautiful from the Inside Out

Just one look at Maria Shriver and daughter Katherine Schwarzenegger Pratt, and it's clear they have the same radiant smile. But what the New York Times best-selling authors also have in common is a similar take on beauty, self-care and wellness — and to celebrate their partnership with probiotic supplement company Renew Life, they shared their everyday approach to those with PEOPLE.

"I've learned everything about skincare from Katherine, and I love that," says Shriver. Growing up, the acclaimed journalist and author, 66, "never" talked "about beauty" with her mother Eunice Kennedy Shriver, who she recalls not having a morning or evening routine.

Instead, Shriver says, her mother focused conversations on other qualities, which in turn helped her have a healthy perspective on beauty. "She always spoke to me about my brain. She was always emphasizing that. So I came to have a philosophy on beauty that, first and foremost, it was something that came from the inside out."

Shriver also recalls that when she was young, "there wasn't much emphasis on products like there is today." But after years of watching her daughters (Katherine, 32, and Christina, 30) she's "learned to value" her skin.

"I grew up putting baby oil on my face and tanning with a reflector. I know, I know. My mother sailed and was out in the sun all the time. But Katherine has always prioritized sunblock. I am the beneficiary of a daughter who's really into that, and reminds me to get into it and shares her product. So, I think that's a really wonderful gift," says Shriver, who is now a sunscreen devotee.

Even though Shriver says she's taking tips from her daughter, Schwarzenegger Pratt says she's learned a tremendous amount from her mother as well.

"I've always looked up to my mom, who wore little to no makeup every single day and really was just the ultimate beauty icon to my sister and me. I grew up with a really great example of natural beauty."

Shriver passed along the "importance of inner beauty from a very early age," Schwarzenegger Pratt adds. "What goes on on the inside exudes on the outside. Being happy on the inside and a great smile [are] the most beautiful things, my mom always said. So, that has always been my philosophy."

Schwarzenegger Pratt hopes to pass along the healthy perspective to her daughter Lyla, 1, as well. "I want that for her. It's such a huge gift to be able to give to a girl."

Shriver and Schwarzenegger also shared the products and practices that keep them feeling good.

"When I think of beauty, I think of health. I did take prenatal vitamins when I was pregnant, but there wasn't a big emphasis like there is today on your gut and supplements," Shriver says. "Practically every woman I talk to is always complaining about digestive and gut issues. We talk about the gut as the second brain, so, when we [discuss] longevity, healthy aging, and Alzheimer's, people talk a lot about your gut," says Shriver, who's worked in the Alzheimer's space for more than 20 years. "My dad [Sargent Shriver] died of Alzheimer's. And, so I've really devoted much of my last 20 years to trying to understand that."

Adds Schwarzenegger Pratt, "My mom does so much in the space of women's health, and sees how little is really tested on women. And, that it's such a huge issue that so many people are dealing with today in a variety of different spaces in the health field and the medical field. So one of the reasons that my mom and I were really drawn to this partnership with Renew Life was that they are tested on women. Growing up and having my mom and I be so openly communicative about each other's health and wellness journeys, this was something that was kind of a no-brainer for both of us."

Shriver also says that me meditation is a must-have in her wellness regimen. "I [do it] every day and that's been a huge gift to me."

"If you feel good, if you feel happy, if you feel healthy, it resonates in your face and your demeanor," she adds.

Meanwhile, Schwarzenegger Pratt loves to get outdoors. "Walking definitely starts my day off in a great way. It's my version of meditation."

Her lasting tip: "You can have fun with makeup and beauty products. But, at the end of the day, knowing how you feel and who you are, who's around you and what you do with your life, your happiness and your joy is really what's most important."