Photo: Factory PR

Miranda Kerr

Miranda Kerr‘s organic skincare line isn’t the only secret behind her signature glow — it’s also motherhood.

Just three months ago, the Australian-born model and entrepreneur, 36, became a mom of three when she welcomed sonMyleswith her husband, Snapchat CEOEvan Spiegel. And she’s loving every second.

“My heart is just so full of joy and happiness,” Kerr told PEOPLE at the launch of herKora Organics‘ new Noni Night AHA Resurfacing Serum at SmogShoppe in Los Angeles on Thursday night. “It’s definitely busy. No day’s ever the same. But we love it. I couldn’t be happier, and I feel very grateful and very blessed to have three healthy boys and a wonderful husband.”

Along with Myles, Kerr also shares 20-month-old sonHartwith Spiegel, 29, and 9-year-old sonFlynnwith her ex,Orlando Bloom. Before welcoming Hart and Myles, Kerr said Flynn wanted nothing more than to have a little brother.

“A long time ago, he said to me, ‘I want a brother,’ ” the model recalled. “Then I said, ‘Well, Evan and I are going to get married first.’ And then hecomes running in the day we got marriedand he was like, ‘Do I have a brother?!’ And I’m like, ‘Not yet!’ ”

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Miranda Kerr.

Miranda Kerr

“I went to a business conference many, many years ago in Australia and this woman was talking about how planning, and even mapping out things months in advance, was one of the keys to her success,” she said. “That really made an impact on me, and it’ssomething that I’ve incorporated into my life.”

“And if I hadn’t, it would be a lot more chaotic,” Kerr continued. “Obviously you have to be flexible, things change. But if you can plan things in advance — like business meetings around the babies’ nap schedules — it’s much more manageable.”

“Time management is something that I feel strongly about,” she added. “It’s something I feel like I’m constantly working on because time is precious, and I want to be there for my childrenand my husband as much as possible. But I also have a business that I’m running, and I feel that it’s important to also take time.”

Evan Spiegel and Miranda Kerr.Miranda Kerr/Instagram

Miranda Kerr Evan Spiegel

Kerr said she tries to fit exercise into her schedule while doing other things, like when going on walks with her husband and children or when “turning the music on and dancing with the kids.”

On top of everything,breastfeeding has proven to bean added challenge for Kerr when it comes to planning her schedule, she told PEOPLE.

“You definitely have to plan,” she said. “So like right before [this] event, I made sure that I pumped because my house is far away from here. So I pumped right before, and then I’ve got to pump any minute. It’s every three hours. Then when I’m with him,I breastfeed every two to three hours. But at least I always have extra milk at home.”

Miranda Kerr’s Kora Organics.Factory PR

Miranda Kerr

“I feel so blessed because our organic chemists are amazing at what they do so I come up with these ideas and then I say, ‘How can we do this to make sure it works really well synergistically with the other products in the line?’ ” she said. “It’s like a layering process, and they’re the formulators. I have the concept, and they put it all together and they send itto me and I try and test the product.”

Kerr told PEOPLE she incorporates the night serum into her daily routine, which is done in five simple steps: “Cleanse, mist, serum, moisturize, oil.” At night, she also likes to add a sleeping mask.

“They’re simple steps, and they really help,” said Kerr, who added that her routine has evolved over the years. “Now I’m incorporating the[Noni Bright] Vitamin C Serumin the morning, and this night serum at night. I feel that’s a really great combination for pigmentation, which is something I feel like I’m constantly aware of because I have three babies. I feel like I’m constantly fighting the pigmentation.”

Miranda Kerr (L) and Olivia Munn at her Noni Night Serum launch.Factory PR

Miranda Kerr

Throughout her last pregnancy, Kerr said she used all of her Kora Organics products on her body.

“I use the body lotion, the body wash and the body oil to help combat stretch marks,” she said. “It really helped maintain the elasticity of my skin.”

“I used all my products throughout my pregnancy for the last three of them,” Kerr added. “I started Kora before my first child was born, and I’ve used all the body products on my children as well since the day they were born — the body lotion, body wash, body oil.”

From L to R: Stella Maxwell, Miranda Kerr and Sofia Richie at the launch of Kerr’s Noni Night Serum.Factory PR

Miranda Kerr

Kerr also said that husband Spiegel has even been using her products lately.

“My husband uses the face scrub, he uses the face oil and I’ve even put the night serum on him,” she said. “Andit really helps his skin!”

While Kora Organics makes four babies for Kerr, she said she’s open to the possibly of having more children.

“I love kids, and I feel so blessed to have three healthy ones,” she said. “I love being a mother of three boys. But I don’t know. I’m definitelyloving where we’re at right nowwith the three of them. And I’m not sure if we will or won’t. I more so know that my husband definitely, probably, wants more, but I’m open.”

source: people.com