"It was just all really exciting, because everyone was screaming and excited," she said, noting that her mother was making a video of her reaction on her iPhone.
Chaput in January told the archdiocese to assemble a panel of coaches, medical experts, and pastors to discuss the rule and recommend whether to uphold it. The panel met in February, and, according to the archdiocesan statement Thursday, voted "by a wide majority" to uphold the ban.
Chris McCune, the league director for CYO football and a panel member, confirmed that there was an "overwhelming feeling" on the panel to uphold the ban, saying members raised concerns about safety issues and teaching techniques that "could be misconstrued as inappropriate for girls," such as blocking.
But Chaput sought counsel from "additional sources," the statement said without elaborating; he considered factors such as the expectations of parents and coaches, legal issues, and the stances of other CYO leagues around the country.
Chaput was not available for comment Thursday, but archdiocesan spokesman Kenneth Gavin said Chaput also considered the public's response, which included hundreds of letters.
"Everything factored into the final decision," Gavin said.
Whatever swayed the archbishop, the Plas were thrilled. Caroline's father, George, said he was "relieved and happy."
"After all the stories and all the panels, at the end of the day, I'm assuming [Chaput] just kind of figured out that if a kid can play, they can play," he said. "So I'm very glad about it."
Caroline's coaches were equally excited. Jim Reichwein, a family friend and coach of her fifth-grade team, said Caroline more than held her own on the gridiron.
"Guys were initially uncomfortable when they lined up against her. Some hesitated. Those that hesitated ended up getting put on their butt," he said. "She was strong, and she played the game the right way."
Her defensive coordinator last year, Darren Bethke, said players would have been devastated had she not been allowed to compete again.
"We're all brothers and sisters on the team," he said. "And the fact they would say they couldn't have one of our family members play the next season. . . . We were pretty upset about the situation."
Female participation in football youth leagues is rare. In 2003, 11-year-old quarterback Jasmine Plummer led her Harvey, Ill., team to victory in the Pop Warner Super Bowl, and last fall, a highlight reel of 9-year-old Sam Gordon playing in her all-boys league in Utah went viral. Gordon was one of the signees on Caroline's petition.
In September, Florida teenager Erin DiMeglio made headlines when she played backup quarterback for her high school's varsity team, and in 2003, Katie Hnida became the first woman to score in an NCAA Division I game when she kicked an extra point for the University of New Mexico.
The ban on girls playing CYO football in Philadelphia dated back at least several years. In 2004, Ashley Brown, then a 5-foot-4 sixth grader from Upper Darby, was not allowed to play.
Brown said she was proud of Caroline for continuing to fight the ban. Asked if it bothered her that the rule was changed almost a decade after she wanted to play, she didn't hesitate.
"Not at all," she said. "Sometimes just a couple things make a difference, and it was all her."
The archdiocese left some wiggle room: According to the statement, the ruling is provisional, and will be "reviewed and revised in the coming seasons, as judged appropriate by the archdiocese."
But George Pla said he was hopeful that his daughter left a mark that will have an impact beyond her own ability to play.
"The good news is, this year, or next year, or two years from now, if there's someone who wants to play, they'll be able to play," he said. "Even if she's a she."
And Caroline, who said she would forgo a celebratory dinner Thursday to attend her basketball banquet, said she would carry this experience with her for years.
"I did learn a really important lesson in life," she said. "If there's something you don't like, you can change it. In the end, it can turn out the way that you want."
Contact Chris Palmer at 609-217-8305, firstname.lastname@example.org, or follow on Twitter @cs_palmer