Amelia Prieto, 15, celebrated her quinceañera amongst family and friends at a pool party about 25 miles west of Havana, Cuba, at La Finca la Corojera in Caimito, Cuba. Amelia walks down the staircase of her Havana apartment building as she leaves for her birthday party. (Sarah L. Voisin/The Washington Post)

Amelia sticks her head out of her father’s car as she waits to go to her party in front of her apartment building in Havana. (Sarah L. Voisin/The Washington Post)

About 30 of Amelia Prieto’s best friends gathered on a street corner in Havana, Cuba, early one Sunday morning in March this year. They all had eager faces and numbered invitations in hand that were surrendered for a prized spot on an old rented Blue Bird school bus. The bus was bursting with energy and transported the kids to a villa about 25 miles outside the city for a private pool party.

The guests squeezed Amelia in her bright yellow party dress and offered their best birthday wishes. The year was a special one, her quinceañera. In many parts of Latin America and elsewhere, this birthday marks the transition from child to a young woman. They wrestled for candy that hit the floor after the piñata burst and flirted in tiny bikinis. After rich food, cake, underwater pranks and cans of beer, they sank into the vintage bus seats struggling to keep their eyes open on the drive back to Havana.

As Amelia ushered in her change to adulthood, Cuba is also changing as its relationship with the United States begins to thaw after the Dec. 17, 2014 announcement by Presidents Obama and Raúl Castro that the countries would begin normalizing long-broken relations. Although hot spots are creeping into the country inviting never-before-seen video chatting with long-lost relatives, and a few business deals have been agreed on, the change is quite slow. By the time the next generation of girls celebrate their quinceañera, what will the country look like?

Amelia gives a big hug to her boyfriend, Antonio Hernandez, 19. (Sarah L. Voisin/The Washington Post)

Amelia has her photo taken with the other girls at the party. (Sarah L. Voisin/The Washington Post)

Yazzua Martinez, 13, lies on the side of the pool during the party. (Sarah L. Voisin/The Washington Post)

Mariela Moreira, 15, is surrounded by friends as she lies on the edge of the pool. (Sarah L. Voisin/The Washington Post)

Several boys at the party laugh as they scramble to collect candy from the piñata. (Sarah L. Voisin/The Washington Post)

Amelia is shocked as she wipes the champagne off her face which her mother, Maria de Jesus, 53, playfully tossed on her. Her father, Luis Prieto, 48, is on the right. (Sarah L. Voisin/The Washington Post)

Amelia throws a glass of champagne at her mother after the same was done to her. (Sarah L. Voisin/The Washington Post)

Arachely Fargie, 16, is pictured at the party. (Sarah L. Voisin/The Washington Post)

Osmany Blen Angarica, 26, center, is pictured at the party. (Sarah L. Voisin/The Washington Post)

Jean Pablo Ortega, 16, dances with Lorena Durruthy, 13, left, and Maria Karina Valdes, 18, at the party. (Sarah L. Voisin/The Washington Post)

The packed bus makes its way back to Havana with the tired partygoers. (Sarah L. Voisin/The Washington Post)

On the way back to Havana after the party. (Sarah L. Voisin/The Washington Post)