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Reese Witherspoon may regularly rub elbows with her fellow movie stars, but even she gets starstruck when it comes to members of the royal family.

The actress opens up about her 2011 meeting with Kate Middleton in her new book, Whiskey in a Teacup, per Marie Claire. Although Witherspoon claimed she was "relatively immune from the obsession with the royals," that all changed when she was about to come face-to-face with the then-newlywed at a reception to mark the Launch of Tusk Trust's U.S. Patron's Circle in Santa Barbara, California.

"The scream that issued from my lips upon receiving [the invitation] — you would have thought I was going to die," writes Witherspoon, 42. "I wake up early, mind you, but on that day I was up at 4 a.m. doing my hair. That's early, even for me."

She continued, " ‘I've never seen you this excited,' my husband said. He wasn't kidding."

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The star shared that there were "rays of happiness shooting out of my face" in photos taken by her husband, Jim Toth, during the ride over to the event.

"I love Kate Middleton that much," she wrote. "And she did not disappoint!"

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"She was just lovely and warm, elegant and composed," Witherspoon writes. "She also told a joke, and I immediately fell under her spell. She's just as magnificent as she seems to be. She's a very compassionate, socially conscious, deeply caring person."

Witherspoon also recognized that Kate's place in the public eye isn't easy.

"It takes a very special person to decide to commit to that kind of life, to choose to be under public scrutiny every moment," writes the actress. "Now that she's in that position, her entire life is in service, forever. I am so in awe of that kind of dedication."

Since Prince Harry‘s marriage to Meghan Markle earlier this year, the worlds of Hollywood and the royals are overlapped more than ever. At the couple's wedding, the celebrity guest list included Oprah Winfrey, George Clooney and Elton John.