Lauren Fishbein was talking about her typical day back home when she suddenly gasped, leaped to her feet, and whispered, “Daddy, daddy, give me a piece of paper. Quick!”

It was the most abrupt end to an interview that this journalist has experienced in 25 years, but the reason was a happy one: Fishbein, a seventh grader from Livingston, N.J., had just spotted Serena Williams walking out to warm up for her doubles on the court adjacent to the one where we sat at Roland Garros.

And Fishbein was not going to let the opportunity slip. Grabbing a pen and a visor, she darted down the steps of the aluminum bleachers, a coltish 12-year-old living her dream—in more ways than one.

On an ordinary day, Fishbein might have been gazing out the window of her classroom at Heritage Middle School. But here she was in Paris, a winner in her first match at the storied Stade Roland Garros, and now she had a chance to meet at an icon of the contemporary game.

Twelve-year-olds don’t typically compete at Roland Garros, but Fishbein had been chosen to represent the U.S. in the Longines Junior Tennis Challenge, an exhibition sponsored by the watch company. Lauren is ranked No. 5 among 12-and-under girls in the Eastern section of the USTA, but it wasn’t the ranking that carried her to Paris.

In order to qualify, each of the girls in the international competition had to write a 300-word essay on philanthropy (her topic: a day she spent helping at a school for children with special needs); those judged to have submitted the best essays took part in an eight-girl playoff. The winner, Fishbein, received an all-expenses-paid trip to Paris to compete in the exhibition.

Lauren’s parents, Nina and Vitaly, also made the trip, along with her coach, Anatoly Teterin, a Russian émigré who has worked with some top pros, including Larisa Savchenko Neiland. But Lauren’s parents and coach are reluctant to push too hard. “She’s in seventh grade,” Nina told me. “We want her to be well-rounded, so she attends a regular school and also takes piano lessons.”

Still, there’s nothing part-time about Fishbein’s tennis. She plays six days a week and travels to compete in USTA sectional tournaments. “It can get hectic,” Nina told me. “When she was traveling to New York for lessons, I would pick her up at school at 3:20 and drive her to Queens on the other side of Manhattan, and we’d just make it there for Lauren’s 6:30 lesson. She would change into her tennis clothes in the car, do homework and eat in the car. But her coach now comes out to New Jersey, so at least that’s easier.”

Fishbein won her first match in Paris easily, beating a 12-year-old from Singapore. “It’s a lot of fun, playing on these courts,” she beamed. “I’ve always wanted to play on these courts, but I always thought I’d be much older when I did.”

Fishbein lost in the second round to an excellent young player from Russia, so she has a way to go if she hopes to be the next Serena Williams. But on this trip, just getting to meet the original Serena seemed reward enough.