"When I saw my face, I kind of went, 'What is that?' " says the 42-year-old

She used to consider herself the youngest person in Hollywood, but now Brooke Shields realizes she doesn’t look the same as she did earlier in her career.

And sometimes it takes an old photo to remind her of that.

“I keep thinking I’m younger than I am,” the Lipstick Jungle star, 42, tells Parade magazine in its new issue. “The other day, I was working with a photographer to recreate an image we had done years ago. When I saw my face, I kind of went, ‘What is that?’ I assumed I was going to look the same, and I didn’t. It was a shock to my system.”

Still, the vibrant actress identifies with young characters for which she’ll read scripts – even if her husband, Chris Henchy, 43, thinks otherwise.

“Sometimes I’ll read a part and identify with the material, and I’ll say, ‘Oh, honey, I really like this,’ ” Shields says. “He’ll look at me like I’m crazy and ask, ‘What’s wrong with you? You’re not in your 20s. You seriously think you can walk in there and get this role? It’s going to a 24-year-old.’ ”

Nevertheless, Shields enjoys a busy life. Besides her TV series, there are daughters Rowan, 4, and Grier, 22 months.

“I’m really proud of my kids, I’m excited about my job, and my marriage is not suffering. It’s not easy, but it’s not falling apart,” she says. “This is the first time in my life that everything is exactly the way I want it to be.”