“The three of us have very different, strong personalities,” says Brooke Shields about her and her two daughters Rowan (21) and Grier (18). “One is a golden retriever puppy. Rowan jumps around. She has energy. She’s funny. The other is an Abyssinian cat. Grier is very even-tempered. She’s flawless and calm.”

In this week’s issue of PEOPLE, Brooke and her daughters, accompanied by their rambunctious pup Tuzi, gave their first in-depth interview and a whole lot of fun just before they head off to college. (Grier is starting her freshman year at Wake Forest University, where Rowan is a senior.) And each of them had a slightly different take on what lies ahead.

“I’m terrified that my kids are out of the house now!” says the 59-year-old actress and beauty icon, who is married to comedy writer and director Chris Henchy. Grier adds: “I’m just as worried about myself as I am about them.”

Rowan explains: “Emotions are strained. I mean, I’ve done it before and she was a wreck. I think she’s really busy now, which is good.” Then she adds with a mischievous smile to her mother: “Unofficially, I hope you and Dad rekindle the flame.”

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Watching her daughters grow into confident young women (who also raid her closet and give her advice on TikTok) has left Brooke feeling “awe,” she says.

“Suddenly they’re not yours anymore,” she notes. “When you realize they’re their own people, you get to know them again. When they reveal themselves to you, it’s a new kind of relationship. I didn’t shape them, but I protected them enough to let them become who they are, and I got out of their way.”

Grier adds, “I feel like we’re friends now. You still discipline us, but I feel like we’re a lot closer.”

Her mother says, “I think if you do it in a healthy way, you start to enjoy the people you really like. They go away and then come back, and now I have so much fun watching and listening to them.”

She gets emotional when she hears what her two daughters have to say about each other. “Grier is extremely loyal and has strong opinions,” says Rowan. “She’s a good judge of other people’s character. She’s very funny when she lets her guard down a little. It’s often a little bit crass, but that’s OK.”

In return, Grier says of her older sister: “She is very spontaneous. She knows how not to let other people’s opinions stress her out, which is something I have to learn as well. And if I need her support, she will do it.”

Brooke adds, “I’m going to cry.”

“They will support each other,” she continues. “They are both tough and strong-willed. The world will not get them down. I am proud of them.”

“I’m really going to miss them,” she admits. “I want to stay on the sidelines, but I’m also looking forward to what lies ahead.”

As founder and CEO of Commence, her hair care line for women over 40, and newly elected president of Actors Equity, the 51,000-member union for actors and managers, the beloved star is also beginning a new chapter.

“The fact that this happens while they’re away is like a magic potion,” she says. “On the other hand, maybe I was doing all this subconsciously to keep myself busy.”

“It’s bittersweet,” she says of her daughters moving out. “But I have Tuzi. She’s my replacement obsession and she’s staying with Mom!”

For more on Brooke Shields and her daughter, read the new issue of PEOPLE.