Brooke Shields Says She Feels Change 'Brewing' as She Turns 59 (Exclusive)

Happy birthday, Brooke Shields!

The Mother of the Bride star, who turns 59 on Friday, May 31, recently told PEOPLE how this phase of her life “feels like the beginning” of a new chapter.

“There’s something sort of brewing and I don’t know what it is, but there’s so much change happening,” she added.

For starters, she and her husband, producer and screenwriter Chris Henchy, 60, will become “empty nesters” this fall, when their younger daughter Grier, 18, leaves for college. Their other daughter, Rowan, 20, is also out of the house and pursuing higher education.

The former child actress and model said she’s also more self-assured as she gets older.

“I'm much more comfortable in my ambition than I used to be. I think I used to feel embarrassed that I had an ambitious part,” added the Suddenly Susan alum.

“I used to think that that was somehow something that I shouldn't be coveting or shouldn't be proud of because it sort of signified, ‘What more do you want?’ That was the way I sort of grew up: ‘Be happy with what you have. Don't want for more. Don't look outside yourself. Just be thankful.’ And then you sort of get to a certain age, you're like, ‘You know what? I do want more and I want to try for it and I want to keep going,’ ” said Shields.

As time goes by, Shields also said she has learned the importance of saying “no.”

“I've learned I don't want to spend time with people I don't want to spend time with. And it's almost not personal,” continued Shields. “Whereas I used to feel compelled to say ‘yes’ to everybody, just running myself ragged, trying to see everybody, do everything everybody wanted.’”

“I'm much more relaxed in being myself,” she said.

As for her birthday plans this year, Shields would like to keep it simple. “I think I'll probably just want dinner somewhere. I don't think I want to make a big deal out of it,” she said.

Next year, she’ll go bigger for her milestone 60th. And hitting that number is not something she fears, either, she said: “I don't have any trepidation about any age.”

Mother of the Bride is now streaming on Netflix.