A group trip to Latvia wound up being the surprise of a lifetime for Claire Kelly after her fiancé popped the question during a beachside excursion.

Claire, the 27-year-old daughter of Arizona Sen. Mark Kelly, tells PEOPLE in an exclusive interview that she was “shocked” when her now-fiancé, Michael Mills, proposed on the beach in Jūrmala, Latvia.

Claire, the founder of digital marketing agency Rise & Shine Social, says the moment was “unforgettable, meaningful and special.”

Claire and Michael — who are based in New York City — were traveling to Latvia with their friends Tereze and Pasha for a week-long holiday.

On their last night in Latvia, before they continued to the South of France with friends, the group made a late dinner reservation at a nearby restaurant.

Michael and Pasha had spent the day, they said, “golfing” — but little did Claire know the two were actually setting up for the main event.

“Because the reservation was on the later side, we decided go check out one last scenic spot in the beautiful country before dinner,” Claire tells PEOPLE. Michael and Tereze, meanwhile, said they would meet the women there.

“We arrived at the beach in Jurmala at 9:30 p.m.,” Claire says. “The planner in me I was panicking just a little that we were late for dinner, but Tereze and her family didn’t seem stressed so I wasn’t as nervous as I would normally be.”

Noting that the “sun was just starting to set,” Claire couldn’t help but think the beach looked “magical.”

“When we got to the beach and started walking over the dune I saw Michael all dressed up for ‘dinner’ standing with his arms behind his back and the biggest grin on his face. I found it strange that he wasn’t running toward me like he normally would when he sees me,” she says.

As Michael remained standing, Claire turned to her friend Tereze, who had begun to record the moment.

“I finally realized in that moment what was happening, although I still had a feeling that it was just a joke. That was until he pulled out the biggest bouquet I had ever seen in my entire life. That’s when it hit me,” she says.

She continues: “I dropped my bag, shoes, and jacket and ran over to him. I kind of blacked out but everything was perfect — The weather, the golden hour, and even the placement. When I ran up to him he strategically placed me exactly where I should be to get the picture perfect proposal of my dreams.”

That picture-perfect moment was documented for posterity by Tereze’s sister Ieva, a professional photographer who captured the entire moment “beautifully,” adds Claire.

The evening culminated in a hidden dinner in the dunes surrounded by bouquets of Claire’s favorite flowers. “My favorite dessert is pavlova and they even found a bakery to make a pavlova for me,” she says.

The secret had been a closely guarded, one with Michael — a vice president at LifeSci Partners — only telling couple’s close friends his plans days prior.

And while it was a surprise to Claire, Michael had been planning the proposal for months, even telling Claire’s father, Sen. Kelly, a few months before the engagement.

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After meeting through mutual friends at a party, the couple began dating on Valentines Day 2021 — a date they picked as “kind of a joke,” Claire notes.

“We said, ‘Let’s go get brunch on Valentines Day and make fun of all the people on dates.’ Now the joke’s on us, since that’s the anniversary of our first date,” she laughs.

Three years later, Claire says. Michael’s “childlike energy” remains one of her favorite qualities.

“He is always so playful and we always have so much fun together. It makes living life together so easy and fun,” she says.

Claire says they plan to wed within the next year in a ceremony as intimate as their proposal.

“Having our engagement be so private, I loved that. It was really a moment for us so I kind of envision something similar for our wedding,” Claire tells PEOPLE.