"As a kid, part of me felt a little beaten up by adults. I wasn't causing any trouble, I wasn't committing a crime," she said. "I just wanted to play baseball with my friends."
In 1971, when Pepe was 11, her coach asked her to try out for the Hoboken (N.J.) New Democrats, a recently chartered Little League team. The bylaws prohibited girls from joining, but her coach, Jimmy Farina, did not see why this girl, who pitched and fielded as well as any boy, should be discriminated against.
Neither did the National Organization for Women, which filed a civil rights suit on Pepe's behalf.
"I was tough as a kid, but in private, my mother remembers me crying," Pepe said Wednesday by phone from Hoboken, where she works for the city as an assistant controller. "When they took my uniform away, I felt stripped, in a way."
In court testimony, Little League's president, Creighton J. Hale, argued that girls were excluded only for their own protection because they were more prone to injuries. Hale said girls' bones were fragile, their muscles were weak, traumatic impact to their breasts could later cause cancer, and if their teeth were damaged, "as a cosmetic matter, [it] would have greater consequences than for boys."
Hale's claims were refuted by Joseph Torg, an orthopedic surgeon who was then director of the Temple University Center for Sports Medicine and Science.
"Their expert was wrong about everything," said Torg, who is still working at age 80. "The thinking at the time was seeped in total ignorance."
The judge ruled in Pepe's favor. Little League appealed and lost. But it took two years for the case to work its way through the courts, and by the time her right to play was affirmed, Pepe was too old to qualify for a team.
"I was always angry that they were judging us by our bones," she said. "I didn't understand. I would ask, 'Why don't they just come and see that I can play and that I am not getting injured?' I felt like they didn't give me a real chance."
Physiologically, at 12 and 13, girls and boys are fairly well matched, said Matt Grady, a pediatric sports medicine specialist at Children's Hospital of Philadelphia. In fact, since girls reach puberty two years ahead of boys on average, Grady said, "they may have a slight competitive advantage."
An earlier growth spurt gives them longer bones that help them pitch better, he said, and stronger leg muscles may help them run faster.
The scales tip once boys' testosterone surges, he said. But there is nothing inherently inferior - or more vulnerable - about young adolescent girls' bodies to keep them from playing baseball with boys their same age.
Pepe knew that instinctively.
"I was a real ballplayer - it was in my blood," she said. "But I had no outlet for my talent."
The third of four children, Pepe said her oldest brother, a Marine who served in Vietnam, wanted her to be a "girly girl." But her father, a longshoreman, and mother, a homemaker, stood behind her wish to play baseball.
"They knew that was what made me happy," she said.
During one of the three games she was allowed to play in 1972, before the league forced her out, her parents took a photograph of her sitting in the dugout looking out at the field.
"I'll never forget the look on my face," Pepe said. "I could read what I was feeling in that moment. I knew something bad was going to happen. Nobody was happy that I was there except for my coach, my teammates, and me."
Even after the legal victory, it took years for public sentiment to change, she said. She went on to play varsity softball at St. Peter's College in Jersey City, N.J., but as much as she enjoyed the sport, she said, her real passion has always been baseball.
After two decades as controller for Hackensack Medical Center, Pepe, now 54, recently went to work for the City of Hoboken and discovered that Farina, her old coach, was one of her coworkers.
All these years, she said, she kept her Hoboken New Democrats baseball cap and her glove safely stored in a closet. On the 30th anniversary of winning her right to play, Little League invited her to the World Series and asked her to donate the hat to its museum.
She did, although later she gave it to the National Baseball Hall of Fame and Museum in Cooperstown, N.Y. But her glove remains with the Little League facility in Williamsport. While there, she met up with Hale, who said his granddaughter was on a Little League team.
"The Little League has been good to me. But they did cause me pain as a child," she said, "and that never, ever goes away."
Pepe watches the Williamsport games every year, she said, and always looks forward to seeing a few girls make the series. This year, she is as smitten with Mo'ne as everyone else, she said.
"Please tell her mother that I'm so happy for her and her family," she said. "That I get to play through her and that she's getting so much positive feedback."
Then she added, "I would love to have her autograph a baseball. 'To Maria from Mo'ne.' That would mean the world to me."